EXHIBIT 99

First Interstate BancSystem
Across Montana and Wyoming

To our shareholders,

First Interstate BancSystem reported first quarter 2005 net income of $11,959,000, or $1.48 per diluted share, compared to $9,718,000 or $1.22 per diluted share in first quarter 2004. Earnings are slightly less than fourth quarter 2004, however, they are the highest first quarter earnings reported in Company history. Return on average equity (ROAE) was 15.53% in first quarter 2005 compared to 14.16% last year, return on average assets (ROAA) was 1.17% versus 1.01%, and efficiency ratio was 64.67% versus 67.16%.

Net interest income of $39,333,000 in first quarter 2005 was $2,850,000 more than first quarter 2004. The net interest margin of 4.39% decreased 1 basis point from the same period last year. Compared to fourth quarter 2004, the net interest margin increased 9 basis points. First quarter 2005 average loans grew $182,206,000, or 7%, while quarterly average deposits grew $143,810,000, or 5%, over the same period last year. Improved credit quality also contributed to the earnings growth in first quarter 2005. The provision for loan loss of $1,625,000 was $793,000, or 33%, lower than first quarter 2004.

Noninterest income of $16,949,000 was $467,000 or 3% higher than first quarter 2004. Income from the origination and sale of residential real estate loans increased $56,000, or 3%, more than first quarter 2004. Additional components of the increase year over year were technology services revenue, debit card income and insurance commission increases of $446,000, $299,000 and $162,000, respectively. Partially offsetting the income increases, a $692,000 loss on the sale of securities was recorded in first quarter 2005. Approximately $46,000,000 of U.S. agency securities were sold and replaced with higher yielding securities which should enhance future portfolio yields.

Noninterest expense was $827,000, or 2%, higher than the comparable quarter in 2004. The increase compared to first quarter 2004 can be attributed to increases in salary and benefits of $1,338,000 and furniture, equipment and occupancy of $1,065,000. In first quarter 2005, we also recorded a $463,000 mortgage servicing impairment reversal compared to a $1,029,000 impairment expense for the first quarter of 2004. Without the effect of mortgage servicing impairment, noninterest expense would have been $2,319,000, or 6.7% higher than last year.

During first quarter 2005, we announced our intent to discontinue operation of our banking facilities at Wal-Mart locations. A loss of $366,000 was recorded relating to costs associated with physically removing

operations from the Wal-Mart facilities. The decision to exit the Wal-Mart locations was strategic and is expected to better serve our Company, and you as shareholders, in the future.

On April 8, 2005, the Company paid a $.48 dividend per common share.

First quarter 2005 saw continued growth of our core business and improving financial results. In order to meet the challenging future, our employees, directors and officers need to continue their dedication to improving efficiency and serving our customers.

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

Financial Highlights
Three Months Ended March 31

(unaudited)	2005		2004		% Change
(in thousands, except per share data)
OPERATING RESULTS
Net income	$	11,959	$	9,718		23.1	%
Diluted earnings per share		1.48		1.22		21.3	%
Dividends per share		0.48		0.34		41.2	%
PERIOD END BALANCES
Assets		4,201,211		3,883,535		8.2	%
Loans		2,769,056		2,568,944		7.8	%
Investment Securities		834,941		807,011		3.5	%
Deposits		3,272,388		3,137,336		4.3	%
Common Stockholders’ Equity		310,951		283,971		9.5	%
Common Shares Outstanding		7,980		7,897		1.1	%
QUARTERLY AVERAGES
Assets		4,160,025		3,851,059		8.0	%
Loans		2,740,492		2,558,286		7.1	%
Investment Securities		859,152		798,187		7.6	%
Deposits		3,250,507		3,106,697		4.6	%
Common Stockholders’ Equity		312,227		276,100		13.1	%
Common Shares Outstanding		7,970		7,908		0.8	%

First Quarter 2005

First Quarter 2005

Condensed Consolidated Statements of Income

	Three Months Ended
	March 31
(unaudited)	2005		2004
(in thousands, except per share data)
Total interest income	$	51,967	$	46,567
Total interest expense		12,634		10,084
Net interest income		39,333		36,483
Provision for loan losses		1,625		2,418
Net interest income after provision for loan losses		37,708		34,065
Noninterest income		16,949		16,482
Noninterest expense		36,396		35,569
Income before taxes		18,261		14,978
Income taxes		6,302		5,260
Net income	$	11,959	$	9,718
COMMON SHARE DATA:
Diluted EPS		1.48		1.22
Dividends		.48		.34
Book value		39.02		35.96
Tangible book value		34.33		31.20
Appraised value		*		52.50

*Currently not available, $63.00 as of December 31, 2004

Selected Ratios

	Three Months Ended
	March 31
(unaudited)	2005			2004
PERFORMANCE
Return on avg common equity		15.53	%		14.16	%
Return on avg common equity excl. market adj of securities		15.43	%		14.07	%
Return on avg assets		1.17	%		1.01	%
Net interest margin, FTE		4.39	%		4.40	%
Efficiency ratio		64.67	%		67.16	%
CREDIT QUALITY (Period End)
Annualized provision for loan losses to average loans		0.24	%		0.38	%
Annualized net charge offs to average loans		0.16	%		0.21	%
Allowance for loan losses to loans		1.54	%		1.56	%
Allowance for loan losses to non-accruing loans		263.51	%		155.24	%
CAPITAL ADEQUACY & LIQUIDITY
Leverage capital ratio		7.67	%		7.30	%
Avg loans to avg deposits		84.31	%		82.35	%

It’s our home too

Condensed Consolidated Balance Sheet

	March 31
(unaudited)	2005		2004
(In thousands)
ASSETS
Cash and due from banks	$	184,559	$	204,541
Federal funds sold		121,890		58,140
Interest bearing deposits		31,158		325
Investment securities		834,941		807,011
Loans		2,769,056		2,568,944
Less: allowance for loan losses		42,660		39,998
Net loans		2,726,396		2,528,946
Premises & equipment, net		119,181		116,314
Accrued interest receivable		22,109		19,112
Goodwill and core deposit intangibles		39,354		40,780
Mortgage servicing rights		18,275		14,164
Company owned life insurance		61,066		52,611
Other assets		42,282		41,591
Total Assets	$	4,201,211	$	3,883,535
LIABILITIES AND STOCKHOLDERS’ EQUITY
Deposits	$	3,272,388	$	3,137,336
Securities sold under repurchase agreements		478,448		336,043
Other liabilities		34,142		30,689
Other borrowed funds		4,001		7,399
Long-term debt		60,043		46,859
Subordinated debenture		41,238		41,238
Total Liabilities		3,890,260		3,599,564
Common stockholders’ equity		310,951		283,971
Total Liabilities and Stockholders’ Equity	$	4,201,211	$	3,883,535

First Interstate BancSystem

P.O. Box 30918 • Billings, Montana 59116 • (406) 255-5390
www.firstinterstatebank.com