EXHIBIT 99

To our shareholders,

We are pleased to report record quarterly net income of $16,746,000, or $2.02 per diluted share, compared to $15,274,000, or $1.88 per diluted share, in third quarter 2005. Return on average equity was 18.01% in third quarter 2006 compared to 18.30% in third quarter 2005, return on average assets was unchanged at 1.39%, and efficiency ratio improved to 59.70% versus 59.96%.

Quarterly Results

Net interest income of $47,802,000 in third quarter 2006 was $3,185,000 more than third quarter 2005. This increase resulted from growth in average loans notwithstanding a decrease in net interest margin. Third quarter 2006 average loans grew $342,965,000, or 12%, over the same period last year. The net interest margin decreased 12 basis points from third quarter 2005 to 4.48% for third quarter 2006. Net interest margin has declined due to growth of higher cost deposits and securities sold under repurchase agreements. Third quarter 2006 average deposits grew $167,380,000, or 5%, due mainly to demand deposit growth, over the same period last year. The provision for loan losses of $2,029,000 was $654,000, or 48%, higher than third quarter 2005.

Noninterest income of $21,378,000 was $3,815,000, or 22%, higher than third quarter 2005. Major components of the increase were gain on sale of assets, technology services revenue, debit card revenue and financial services revenue increases of $1,662,000, $717,000, $375,000 and $356,000, respectively. Gain on sale of assets increased as a result of a $1,811,000 loss on sale of securities recorded in third quarter 2005 with no such loss recorded in third quarter 2006.

Noninterest expense of $41,300,000 was $4,057,000, or 11%, higher than the comparable quarter in 2005. Salary and benefits expense increased $1,689,000, or 8%, as compared to third quarter 2005 primarily due to inflationary wage increases and higher incentive bonus and profit sharing accruals. Also contributing to the increase in salary and benefits was the implementation of a new accounting standard which required us to record $163,000 of expense in third quarter 2006 for stock option awards; this expense was not recognized in prior years under the prior accounting standards applicable to stock options. In addition, a $654,000 mortgage servicing impairment was recorded in third quarter 2006 compared to a $985,000 impairment reversal for the third quarter of 2005.

On October 6, 2006, we paid a $.61 dividend per common share. The Board of Directors approved a resolution on July 27, 2006 to increase future quarterly dividends to $.61 per common share until further notice.

Year to Date

On a year to date basis, net income of $49,017,000, or $5.92 per diluted share, was $8,904,000, or 22%, higher than net income of $40,113,000, or $4.94 per diluted share in the first three quarters of 2005. Return on average equity was 18.05% in the first three quarters of 2006 compared to 16.82% for the same period last year, return on average assets was 1.40% versus 1.26%, and efficiency ratio was 59.12% versus 62.79%.

Financial Highlights
Three Months ended September 30

(unaudited)	2006		2005		%Change
(in thousands except per share data)
OPERATING RESULTS
Net income	$	16,746	$	15,274		9.6	%
Diluted earnings per share		2.02		1.88		7.	%
Dividends per share		0.58		0.48		20.8	%
PERIOD END BALANCES
Assets		4,823,959		4,457,739		8.2	%
Loans		3,288,470		2,982,325		10.3	%
Investment securities		1,051,000		887,912		18.4	%
Deposits		3,616,063		3,477,115		4.0	%
Common stockholders’ equity		388,482		342,167		13.5	%
Common shares outstanding		8,160		8,097		0.8	%
QUARTERLY AVERAGES
Assets		4,767,599		4,369,721		9.1	%
Loans		3,272,203		2,929,238		11.7	%
Investment securities		1,015,254		894,369		13.5	%
Deposits		3,558,325		3,390,945		4.9	%
Common stockholders’ equity		368,980		331,174		11.4	%
Common shares outstanding		8,093		7,981		1.4	%

When comparing the year to date performance of 2006 to 2005, there are some items that affect comparability. One such item is loss on sale of securities. In conjunction with a restructuring of our investment portfolio in 2005, losses of $2,941,000 were recognized in 2005 compared to gains of $23,000 in 2006. In addition, $266,000 of mortgage servicing impairments were recorded in 2006 compared to $1,297,000 of impairment reversals in 2005. Also, in the first three quarters of 2005, we recorded $952,000 of expenses related to the closure of Wal-Mart branches compared to $23,000 in the first three quarters of 2006.

The Company continued to improve operational efficiency and maintained the efficiency ratio under 60% on a year to date basis. This progress would not be possible without the dedication of our talented team of employees, officers, and directors. Their commitment to providing our customers with a high level of personalized service continues to show in the financial results of the Company. Thanks again for contributing to the continued success of First Interstate BancSystem.

Lyle R. Knight	Terrill R. Moore
President	Executive Vice President
Chief Executive Officer	Chief Financial Officer

Third Quarter 2006

Condensed Consolidated Statements of Income

	Three Months Ended				Nine Months Ended
	September 30				September 30
(unaudited)	2006		2005		2006			2005
(in thousands, except per share data)
Total interest income	$	76,416	$	61,423	$	214,943		$	168,934
Total interest expense		28,614		16,806		75,562			44,112
Net interest income		47,802		44,617		139,381			124,822
Provision for loan losses		2,029		1,375		6,360			4,365
Net interest income after provision for loan losses		45,773		43,242		133,021			120,457
Noninterest income		21,378		17,563		60,557			52,251
Noninterest expense		41,300		37,243		118,211			111,181
Income before taxes		25,851		23,562		75,367			61,527
Income taxes		9,105		8,288		26,350			21,414
Net income	$	16,746	$	15,274	$	49,017		$	40,113
COMMON SHARE DATA:
Diluted EPS		2.02		1.88		5.92			4.94
Dividends		0.58		0.48		1.66			1.38
Book value						47.61			42.26
Tangible book value						43.03			37.64
Appraised value						77.25	*		65.50	**

*	Based on the latest independent appraised minority share valuation as of June 30, 2006, effective for transactions on or after August 9, 2006.
**	Based on the independent appraised minority share valuation as of June 30, 2005.

Selected Ratios

	Three Months Ended						Nine Months Ended
	September 30						September 30
(unaudited)	2006			2005			2006			2005
PERFORMANCE
Return on avg common equity		18.01	%		18.30	%		18.05	%		16.82	%
Return on avg common equity excl. market adj of securities		17.24	%		18.19	%		17.52	%		16.59	%
Return on avg assets		1.39	%		1.39	%		1.40	%		1.26	%
Net interest margin, FTE		4.48	%		4.60	%		4.50	%		4.47	%
Efficiency ratio		59.70	%		59.96	%		59.12	%		62.79	%
CREDIT QUALITY (Period End)
Annualized provision for loan losses to average loans								0.27	%		0.21	%
Annualized net charge offs to average loans								0.08	%		0.15	%
Allowance for loan losses to loans								1.43	%		1.45	%
Allowance for loan losses to non-accruing loans								293.76	%		257.73	%
CAPITAL ADEQUACY & LIQUIDITY
Leverage capital ratio								8.14	%		8.01	%
Avg loans to avg deposits								90.45	%		85.55	%

Condensed Consolidated Balance Sheet

	September 30
(unaudited)	2006		2005
(In thousands)
ASSETS
Cash and due from banks	$	180,513	$	203,983
Federal funds sold		21,354		105,150
Interest bearing deposits		5,360		14,874
Investment securities		1,051,000		887,912
Loans		3,288,470		2,982,325
Less: allowance for loan losses		46,957		43,213
Net loans		3,241,513		2,939,112
Premises & equipment, net		119,796		120,086
Accrued interest receivable		34,046		26,931
Goodwill and core deposit intangibles		37,853		38,847
Mortgage servicing rights		23,708		20,558
Company owned life insurance		64,071		61,975
Other assets		44,745		38,311
Total Assets	$	4,823,959	$	4,457,739
LIABILITIES AND STOCKHOLDERS’ EQUITY
Deposits	$	3,616,063	$	3,477,115
Federal funds purchased		63,830		0
Securities sold under repurchase agreements		634,581		495,269
Other liabilities		45,260		38,499
Other borrowed funds		5,941		6,435
Long — term debt		28,564		57,017
Subordinated debenture		41,238		41,238
Total Liabilities		4,435,477		4,115,573
Common stockholders’ equity		388,482		342,166
Total Liabilities and Stockholders’ Equity	$	4,823,959	$	4,457,739