8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): November 3, 2017 (November 5, 2017)

NorthWestern Corporation

(Exact name of registrant as specified in its charter)

Delaware (State or other jurisdiction of incorporation)		1-10499 (Commission File Number)	46-0172280 (IRS Employer Identification No.)
3010 W. 69th Street Sioux Falls, South Dakota (Address of principal executive offices)			57108 (Zip Code)
	(605) 978-2900 (Registrant's telephone number, including area code)

Indicate by check mark whether the registrant is an emerging growth company as defined in as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging Growth Companyo

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

[ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 7.01Regulation FD Disclosure.

On November 5-7, 2017, Robert Rowe, president and chief executive officer, Brian Bird, vice president and chief financial officer, Curtis Pohl, vice president - distribution, and Travis Meyer, director - corporate finance and investor relations officer, of NorthWestern Corporation d/b/a NorthWestern Energy (NYSE: NWE) (the “Company”), will be in Orlando, Florida, at the Edison Electric Institute's 52^nd Annual Financial Conference conducting one-on-one meetings with analysts, investors, and other third parties. During these meetings, they will be providing certain information concerning the Company in a slide presentation and will be reaffirming the Company's adjusted non-GAAP earnings guidance of $3.30 to $3.45 per diluted share and providing preliminary earnings guidance for 2018 to be in the range of $3.35 to $3.50per diluted share.

    A copy of the slide presentation is being furnished pursuant to Regulation FD as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference. The information in the slide presentation shall not be deemed to be "filed" for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liability of that section. Furthermore, the slide presentation shall not be deemed to be incorporated by reference into the Company's filings under the Securities Act of 1933, as amended, or under the Securities Exchange Act of 1934, as amended, except as set forth with respect thereto in any such filing.

Item 9.01 Financial Statements and Exhibits.

EXHIBIT NO.	DESCRIPTION OF DOCUMENT
99.1*	Slide presentation dated November 5-7, 2017

* filed herewith

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	NORTHWESTERN CORPORATION
By:	/s/ Timothy P. Olson
	Timothy P. Olson
	Corporate Secretary

Date: November 3, 2017

Index to Exhibits

EXHIBIT NO.	DESCRIPTION OF DOCUMENT
99.1*	Slide presentation dated November 5-7, 2017

* filed herewith

EX-99.1

8-K November 3, 2017 EEI Financial Conference November 5-7, 2017 Hebgen Reservoir – south of Big Sky, MT

2 Forward Looking Statements Forward Looking Statements During the course of this presentation, there will be forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements often address our expected future business and financial performance, and often contain words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” or “will.” The information in this presentation is based upon our current expectations as of the date hereof unless otherwise noted. Our actual future business and financial performance may differ materially and adversely from our expectations expressed in any forward-looking statements. We undertake no obligation to revise or publicly update our forward-looking statements or this presentation for any reason. Although our expectations and beliefs are based on reasonable assumptions, actual results may differ materially. The factors that may affect our results are listed in certain of our press releases and disclosed in the Company‟s most recent Form 10-K and 10-Q along with other public filings with the SEC. NorthWestern Corporation dba: NorthWestern Energy Ticker: NWE Trading on the NYSE www.northwesternenergy.com Corporate Office 3010 West 69th Street Sioux Falls, SD 57108 (605) 978-2900 Investor Relations Officer Travis Meyer 605-978-2967 travis.meyer@northwestern.com Company Information

About NorthWestern 3 Montana Operations Electric 363,800 customers 24,450 miles – transmission & distribution lines 809 MW nameplate owned power generation Natural Gas 194,100 customers 7,250 miles of transmission and distribution pipeline 18 Bcf of gas storage capacity Own 61 Bcf of proven natural gas reserves Nebraska Operations Natural Gas 42,300 customers 787 miles of distribution pipeline South Dakota Operations Electric 63,200 customers 3,550 miles – transmission & distribution lines 440 MW nameplate owned power generation Natural Gas 46,200 customers 1,673 miles of transmission and distribution pipeline

NWE - An Investment for the Long Term 4 • 100% regulated electric & natural gas utility business with over 100 years of operating history • Solid economic indicators in service territory • Diverse electric supply portfolio ~54% hydro & wind Black Eagle dam Pure Electric & Gas Utility Solid Utility Foundation Strong Earnings & Cash Flow Attractive Future Growth Prospects Financial Goals & Metrics Best Practices Corporate Governance • Residential electric & gas rates below national average • Solid system reliability (EEI 2nd quartile) • Low leaks per 100 miles of pipe (AGA 1st quartile) • Solid JD Power Overall Customer Satisfaction scores • Disciplined maintenance capital investment program to ensure safety and reliability • Significant investment in renewable resources (hydro & wind) will provide long-term energy supply pricing stability for the benefit of customers for many years to come • Further opportunity for energy supply investment to meet significant capacity shortfalls • Consistent track record of earnings & dividend growth • Strong cash flows aided by net operating loss carry- forwards anticipated to be available into 2021 • Strong balance sheet & investment grade credit ratings • Debt to total capitalization ratio of 50%-55% with liquidity of $100 million or greater • Targeted 7%-10% total shareholder return (eps growth plus dividend yield) • Targeted dividend payout ratio of 60%-70% (at the bottom of this range in 2017)

A Diversified Electric and Gas Utility 5 NorthWestern‟s „80/20‟ rules: Approximately 80% Electric, 80% Residential and 80% Montana Nearly $3.5 billion of rate base investment to serve our customers Data as of 12/31/2016.

6 Highly Carbon-Free Supply Portfolio Based upon 2016 MWH‟s of owned and long-term contracted resources. Approximately 54% of our total company owned and contracted supply is carbon-free. NorthWestern does not own all the renewable energy certificates (RECs) generated by contracted wind, and periodically sells its own RECs with proceeds benefiting retail customers. Accordingly, we cannot represent that 100% of carbon-free energy in the portfolio was delivered to our customers.

Strong Utility Foundation 7  Solid and improving JD Power Overall Customer Satisfaction Scores  Residential electric and natural gas rates below national average  Solid electric system reliability and low gas leaks per mile

Solid Economic Indicators 8 • Customer growth rates historically exceed National Averages. • Unemployment rates in all three of our states are meaningfully below National Average. Source: NorthWestern customer growth - 2008-2016 Forms 10-K Unemployment Rate: US Department of Labor via SNL Database 2/21/17 Electric: EEI Statistical Yearbook (published December 2015, table 7.2) Natural Gas: EIA.gov (Data table "Number of Natural Gas Consumers") Source: Company 10K’s, 2014/2015 EEI Statistical Yearbook and EIA.gov Black Eagle Power House

A History of Growth 9 2008-2016 CAGR‟s: GAAP EPS: 8.5% - Non-GAAP EPS: 7.6% - Dividend: 5.3% See appendix for “Non-GAAP Financial Measures” $2.60 - $2.75 $3.10 - $3.30 $3. 0-$3.40 $3.30-$3.50

Track Record of Delivering Results 10 Return on Equity within 9.5% - 11.0% band over the last 6 years with average of 10.4% on GAAP earnings. See appendix for “Non-GAAP Financial Measures” Total Shareholder Return is better than our 13 peer average for the 10 year period but lags in the 1, 3 & 5 year periods. * Peer Group: ALE, AVA, BKH, EE, GXP, IDA, MGEE, OGE, OTTR, PNM, POR, VVC, WR

Investment for Our Customers‟ Benefit 11 Over the past 8 years we have been reintegrating our Montana energy supply portfolio and making additional investments across our entire service territory to enhance system safety, reliability and capacity. We have made these enhancements with minimal impact to customers‟ bills while maintaining bills lower than the US average. As a result we have also been able to deliver solid earnings growth for our investors. 2008-2016 CAGRs Estimated Rate Base: 14.8% GAAP Diluted EPS: 8.4% NWE typical electric bill: 2.2% NWE typical natural gas bill: (7.5%) US average electric bill: 1.7%* US average natural gas bill: (4.0%)**

Balance Sheet Strength and Liquidity 12 Solid credit ratings, liquidity in excess of $100 million target, and debt to cap within our targeted 50%-55% range. Our next debt maturity ($250 million 6.34% Montana First Mortgage Bonds due in 2019) is expected to be redeemed with a recently signed bond purchase agreement to issue $250M of MT FMB at a fixed rate of 4.03% maturing in 2047. We expect to close on transaction in early November 2017. Dotted lines in 2019 & 2047 include refinancing to close in November 2017

While maintenance capex and total dividend payments have continued to grow since 2011 (12.9% and 13.0% CAGR respectively), Cash Flow from Operations (CFO) has continued to outpace maintenance capex by approximately $30 million per year. 2016 CFO is less than 2015 largely due to $30.8M refund to customers related to FERC/DGGS ruling and $7.2M refund to customers for difference in SD Electric interim & final rates. With the addition of production tax credits from the Beethoven Wind project and continued flow-through tax benefits, we anticipate our effective tax rate rising only into the low-twenties by 2020. Additionally, we expect NOLs to be available into 2021 to reduce cash taxes. (See appendix for “Non-GAAP Financial Measures” relating to free cash flow and disclaimer on NOL’s) Strong Cash Flows 13

Experienced Leadership & Solid Corp. Governance 14 Board of Directors (left to right) Executive Management Team (left to right) Linda G. Sullivan – Independent Director since April 27, 2017 – Audit Committee Dana J. Dykhouse – Independent Director since January 30, 2009 – Human Resources (chair) and Audit Committees Britt E. Ide – Independent Director since April 27, 2017 – Governance & Innovation Committee Jan R. Horsfall – Independent Director since April 23, 2015 – Audit and Governance & Innovation Committees Anthony T. Clark – Independent Director since December 6, 2016 – Governance & Innovation Committee Robert C. Rowe - CEO & President – Director since August 13, 2008 Dr. E. Linn Draper Jr. -Chairman of the Board – Independent Director since November 1, 2004 Julia L. Johnson – Independent Director since November 1, 2004 – Governance & Innovation (chair) and Human Resources Committees Stephan P. Adik – Independent Director since November 1, 2004 – Audit (chair) and Human Resources Committees Patrick R. Corcoran – VP Gov’t & Regulatory Affairs – current position since 2002 Crystal D. Lail – VP & Controller – current position since 2015 Curtis T. Pohl – VP Distribution – current position since 2003 Bobbi L. Schroeppel – VP Customer Care, Communications & Human Resources – current position since 2002 Brian B. Bird – VP & CFO – current position since 2003 Heather H. Grahame – VP & General Counsel – current position since 2010 Robert C. Rowe - President & CEO – current position since 2008 John D. Hines – VP Supply – current position since 2011 Michael R. Cashell – VP Transmission – current position since 2011

Recent Significant Achievements 15 Strong year for safety in 2016 • Fewest OSHA recordable events of any year. • Best year for least lost time incidents. Record best customer satisfaction scores • Received our best Overall Customer Satisfaction scores in the JD Power residential utility survey in 2016. Corporate Governance Finalist • NorthWestern‟s proxy statement has been recognized as a finalist by Corporate Secretary magazine for Best Small to Mid-Cap Proxy Statement for several years, including 2016 & 2017, and won the award in 2014. Recognized for Strong Dividend • In March 2016, NorthWestern was added to the NASDAQ US Broad Dividend AchieversTM Index, which aims to represent the country‟s leading stocks by dividend yield in addition to Dow Jones US Dividend Select TM Index in 2015. Echo Lake Nordic Trail New Board Members • Anthony T. Clark, senior advisor at Wilkenson Barker Knauer LLP and former FERC commissioner and North Dakota Public Service Commissioner, joined in December 2016 • Britt E. Ide, president of Ide Energy & Strategy, joined in April 2017 • Linda G. Sullivan, exec. vice president and chief financial officer of American Water, joined in April 2017

Looking Forward 16 Montana Regulatory • Working toward successful implementation of new Power Cost and Credit Adjustment Mechanism (PCCAM) • Anticipate filing an electric rate case by September 2018 (based on a 2017 test year). Cost control efforts • Continue to monitor costs, including labor, benefits and property tax valuations to mitigate increases Continue to invest in our T&D infrastructure. • Transition from DSIP/TSIP to overall infrastructure capital investment plan • Natural gas pipeline investment (Integrity Verification Process and PHMSA1 Requirements) • Advanced Metering Infrastructure (AMI) investment Refining our Supply Plan in Montana • Continue to work with Montana Public Service Commission and other stakeholders to refine energy supply plan to resolve significant capacity deficit Continue to search for natural gas reserve acquisition opportunities • Acquisitions at a price that benefits both customers and shareholders 1. Pipeline & Hazardous Materials Safety Administration Much of our focus in the next year will be on the electric rate case in Montana and controlling our costs to benefit all stakeholders while continuing to invest in our core business to provide safe and reliable energy for our all of our customers.

Financing Activities 17 Long-Term Debt Refinancing • In October 2017, we priced $250 million principal, 4.03% - 30 year Montana First Mortgage Bonds • We expect to close the transaction in early November 2017. • Proceeds used to redeem existing $250 million – 6.34% Montana First Mortgage Bonds due in 2019 At-The-Market Equity Offering Program • Initiated in September 2017 • Proceeds to repay or refinance debt (including short-term debt), fund capital expenditures and other general corporate purposes • During the third quarter 2017 we sold 83,769 shares of common stock at an average price of $59.56 per share, for a total of approximately $5 million of proceeds. Big Sky Substation Expect annual interest expense savings of over $5 million net of make-whole amortization We anticipate issuing the remaining $95 million, from time to time, by the end of 2018.

Property Tax Tracker Rules Filing – In March 2017, the MPSC proposed new rules to establish minimum filing requirements for property tax trackers. • Current MT Property tax tracker rules allows recovery of 60 percent of the change in state and local taxes and fees. • In June 2017, the MPSC adopted new rules to establish minimum filing requirements with some of the rules appearing to be based on a narrow interpretation of the enabling statute and suggest that the MPSC will challenge the amount and allocation of these taxes to customers. We expect to submit our annual filing in December 2017, with resolution during the first quarter of 2018. Montana Natural Gas Rate Filing • In June 2017, we reached a settlement agreement with intervenors. In August 2017,the MPSC’s issued a final order accepting the settlement with modifications resulting in an annual revenue increase $5.1 million, ROE at 9.55% with ROR of 6.96% and including an annual reduction in production rates to reflect depletion until our next rate filing. Rates were effective September 1, 2017. • While the final order reflects an annual increase of approximately $5.1 million, we expect the increase in 2018 to be approximately $2.0 million due to the inclusion in 2017 of four months of increased rates and the step down of gas production rates to reflect depletion. 18 Regulatory & Legal Update FERC / DGGS – April 2014 order regarding cost allocation at DGGS between retail & wholesale customers • FERC denied our request for rehearing in May 2016 • Required us to make refunds in June 2016 of $27.3 million plus interest • We filed a petition for review with the US Circuit Court of Appeals for the District of Columbia Circuit in June 2016 and oral argument is scheduled for December 1, 2017. • We do not expect a decision until the first quarter of 2018, at the earliest. Colstrip – In May 2016, the MPSC issued a final order disallowing recovery of certain costs included in the electric supply tracker related to a 2013 Unit 4 outage • Appeals have been filed in two Montana district courts regarding disallowance. • We believe we are likely to receive orders from the courts in these matters within the next 12 months.

Montana - Implementation of HB 193 19 PCCAM - as proposed by NorthWestern Procedural Timeline: May 2017 MPSC issued Notice of Commission Action (NCA) initiating process July 7, 2017 MPSC issued additional NCA addressing arguments in our motion to reconsider the original NCA. (July 7, 2017 – D2017.5.39). July 14, 2017 We proposed electric Power Cost and Credit Adjustment Mechanism (PCCAM) with the MPSC. Aug. 1, 2017 MPSC concluded work session declining to require NWE to submit additional filing. Sept. 20, 2017 MPSC established procedural schedule for PCCAM. Nov. 13, 2017 Final day for Intervenor testimony Jan. 12, 2018 Final day for NWE to file rebuttal testimony Mar. 12, 2018 Hearing on PCCAM. Background: In April 2017, the Montana legislature passed House Bill 193 (HB 193), repealing the statutory language that provided for mandatory recovery of our prudently incurred electric supply costs, effective July 1, 2017. The enacted legislation gives the MPSC discretion whether to approve an electric supply cost adjustment mechanism. In support of the passage of HB 193, A MPSC Commissioner testified before Senate requesting the bill should be passed “to subject NorthWestern to the exact same regulatory treatment as Montana Dakota Utilities.” The proposed PCCAM, with the 90% / 10% risk sharing mechanism was designed to be responsive to the Commission‟s advocacy. If the MPSC approves the PCCAM, we expect it will apply the mechanism to variable costs on a retroactive basis to the effective date of HB 193 (July 1, 2017)

20 Regulatory Update (continued) Qualified Facilities (QF) Decision: Under the Public Utility Regulatory Policies Act (PURPA), electric utilities are required, with exceptions, to purchase energy and capacity from independent power producers that are Qualified Facilities (QF). • In July 2017, the MPSC issued a final order in the QF-1 docket that adopted generally lower rates and shortened the maximum contract length for new QFs to 10 years (with a rate adjustment after 5 years). The MPSC also ordered that any future resources, be subject to the same period, saying it “will not initially authorize NorthWestern rate revenue for more than ten years” and “at the end of the ten year period the Commission may provide for subsequent rate revenue based on a consideration of the value of the asset to customers and not necessarily based on the costs of the resource.” • We and other parties filed motions for reconsideration of this decision. The MPSC voted in October 2017 to revise the initial order extending the contract length to 15 years and to continue to apply the contract term to both QF contracts and our future electric supply resources, however, it has not yet issued a final order. Based on the MPSC‟s October 2017 vote, we expect that the decision will result in substantially lower rates for future QF contracts. • We have significant generation capacity deficits and negative reserve margins, and our 2016 resource plan identified price and reliability risks to our customers if we rely solely upon market purchases to address these capacity needs. In addition to our responsibility to meet peak demand, national reliability standards effective July 2016 require us to have even greater dispatchable generation capacity available and be capable of increasing or decreasing output to address the irregular nature of intermittent generation such as wind or solar. As a result of the MPSC‟s July decision, we suspended a competitive solicitation process to determine the lowest-cost / least-risk approach for addressing capacity needs in Montana. A final determination regarding the competitive solicitation will be dependent upon reviewing the MPSC‟s revised order (based on the October reconsideration). We anticipate the order to be issued during the fourth quarter of 2017.

Critical Capacity Shortfall 21 The resource initiatives and actions developed in our 2015 Electricity Supply Resource Procurement Plan identify the critical future needs of our portfolio, including solutions to resolve our current negative planning reserve margin of 28%, which is projected to grow to 50% by 2035 without any additional owned or contracted resources added to our portfolio. As a result of a July 2017 decision by the MPSC regarding maximum contract length for all new generation, we suspended a competitive solicitation process to determine the lowest-cost / least-risk approach for addressing our intermittent capacity and reserve margin needs in Montana. A final determination regarding the competitive solicitation will be dependent upon reviewing the MPSC's revised order resulting from an October 2017 decision (expected during the fourth quarter 2017). Planning Reserve Margin

Capital Spending 22 Approximately $100 million of this capital spend is earmarked for Montana generation capacity and could be impacted by the recent 15 year contract limitations implemented by the MPSC. We suspended a competitive solicitation process for addressing capacity needs in Montana and a final determination will be dependent upon reviewing the MPSC’s revised order in the matter (expected in the fourth quarter 2017). We anticipate funding the expenditures with a combination of cash flows, aided by NOLs now anticipated to be available into 2021, long-term debt and our current $100 million equity distribution program. If other opportunities arise that are not in the above projections, additional equity funding may be necessary.

Preliminary 2017 to 2018 Bridge Preliminary & Non-GAAP 2017 Midpoint → 2018 Midpoint Prior to ATM Equity Dilution: $3.37 → $3.54 = 5.0% Increase After anticipated ATM Equity Dilution: $3.37 → $3.43 = 1.8% Increase Dividend Growth $2.10 → $2.20 = 4.8% increase Continued investment in our system to serve our customers and communities is expected to provide a targeted 7-10% total return to our investors through a combination of earnings growth and dividend yield over the long-term. However in light of recent regulatory headwinds and reduced & delayed generation spending, we anticipate in the near- term to be at the lower end of the range. Assumptions included in Preliminary 2018 Guidance includes, but is not limited to, the following major assumptions: • Normal Weather in our service territories; • Recovery of Montana energy supply costs as proposed in our pending Power Cost and Credit Adjustment Mechanism; • A consolidated income tax rate of 8% - 12% of pre-tax income; and • Diluted average shares of approximately 50.3 million. 23

Conclusion 24 Best Practices Corporate Governance Pure Electric & Gas Utility Solid Utility Foundation Strong Earnings & Cash Flows Attractive Future Growth Prospects

Non-GAAP Financial Measures (1 of 2) 25 Disclaimer on Net Operating Net Operating Losses (NOL’s): The expected tax rate and the expected availability of NOLs are subject to significant business, economic, regulatory and competitive uncertainties and contingencies, many of which are beyond the control of the Company and its management, and are based upon assumptions with respect to future decisions, which are subject to change. Actual results will vary and those variations may be material. For discussion of some of the important factors that could cause these variations, please consult the “Risk Factors” section of the preliminary prospectus. Nothing in this presentation should be regarded as a representation by any person that these objectives will be achieved and the Company undertakes no duty to update its objectives.

Non-GAAP Financial Measures (2 of 2) 26 The data presented in this presentation includes financial information prepared in accordance with GAAP, as well as other Non- GAAP financial measures such as Gross Margin (Revenues less Cost of Sales), Free Cash Flows (Cash flows from operations less maintenance capex and dividends) and Net Debt (Total debt less capital leases), that are considered “Non-GAAP financial measures.” Generally, a Non-GAAP financial measure is a numerical measure of a company’s financial performance, financial position or cash flows that exclude (or include) amounts that are included in (or excluded from) the most directly comparable measure calculated and presented in accordance with GAAP. The presentation of Gross Margin, Free Cash Flows and Net Debt is intended to supplement investors’ understanding of our operating performance. Gross Margin is used by us to determine whether we are collecting the appropriate amount of energy costs from customers to allow recovery of operating costs. Net Debt is used by our company to determine whether we are properly levered to our Total Capitalization (Net Debt plus Equity). Our Gross Margin, Free Cash Flows and Net Debt measures may not be comparable to other companies’ similarly labeled measures. Furthermore, these measures are not intended to replace measures as determined in accordance with GAAP as an indicator of operating performance.

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