Branch Network
First Interstate Bank Locations & Branches Billings, Montana
BankRegReports is independent of First Interstate Bank and never asks for online banking logins or passwords.
First Interstate Bank operates 274 branches from its headquarters in Billings, MT, .
First Interstate Bank branch network
Its 274 branches span 10 states and 200 cities. The most are in SOUTH DAKOTA (46), IOWA (45) and MONTANA (44). MONTANA holds 28.0% of its branch deposits. Billings, MT has the most of its branches, 9. Its largest office by deposits is its main office in Billings, MT, with $1.07B (4.9% of its branch deposits). On June 30, 2025 it had 302 branches, 28 more than in 2026.
First Interstate Bank at a glance
Its CET1 capital ratio was 14.32% at Q2 2026, comfortably above the 7% level required once the capital conservation buffer is included.
- Total assets, Q2 2026
- $25.79B
- CET1 ratio, Q2 2026
- 14.32%
- Deposit insurance
- FDIC
- Regulator
- Federal Reserve
- Established
- 1916
Full financial profile · Is First Interstate Bank safe? · Routing number
Deposit market share
Share of all FDIC-insured deposits held in each area, from the June 30, 2026 Summary of Deposits. Rank 1 is the largest holder. Shares are by bank charter, not by holding company.
| Area | Rank | Deposit share | Deposits |
|---|---|---|---|
| City: Billings, MT (9 branches) | 1 of 11 | 25.4% | $1.80B |
| State: MT (44 branches) | 3 of 48 | 15.7% | $6.09B |
Ranked by total assets among banks headquartered in the state: Largest banks in Montana.
Share by county and metro area
First Interstate Bank's share of FDIC-insured deposits in the counties and metro areas where it has branches, from the June 30, 2026 Summary of Deposits. Up to the ten largest of each are shown, by the bank's deposits. Rank 1 is the largest holder. Banks only: credit unions are not in the Summary of Deposits.
Counties
| County | Rank | Deposit share | Deposits | County total |
|---|---|---|---|---|
| Yellowstone, MT (10 branches) | 1 of 12 | 24.6% | $1.82B | $7.43B |
| Deschutes, OR (9 branches) | 1 of 10 | 22.5% | $1.14B | $5.06B |
| Minnehaha, SD (10 branches) | 6 of 25 | 0.2% | $954.6M | $478.92B |
| Missoula, MT (3 branches) | 2 of 11 | 20.9% | $824.9M | $3.95B |
| Ada, ID (10 branches) | 8 of 23 | 5.0% | $803.2M | $15.98B |
| Gallatin, MT (4 branches) | 3 of 16 | 13.2% | $689.8M | $5.24B |
| Douglas, NE (8 branches) | 11 of 43 | 2.0% | $657.5M | $33.32B |
| Flathead, MT (7 branches) | 2 of 12 | 15.6% | $620.8M | $3.97B |
| Pennington, SD (7 branches) | 1 of 10 | 18.8% | $616.4M | $3.27B |
| Natrona, WY (3 branches) | 2 of 9 | 22.4% | $580.6M | $2.59B |
Metro areas
| Metro area | Rank | Deposit share | Deposits | Metro total |
|---|---|---|---|---|
| Billings, MT (13 branches) | 1 of 13 | 24.9% | $1.98B | $7.95B |
| Boise City, ID (13 branches) | 5 of 24 | 5.9% | $1.14B | $19.36B |
| Bend, OR (9 branches) | 1 of 10 | 22.5% | $1.14B | $5.06B |
| Sioux Falls, SD (12 branches) | 10 of 39 | <0.1% | $1.04B | $1.13T |
| Omaha-Council Bluffs, NE-IA (14 branches) | 7 of 77 | 2.4% | $1.01B | $42.59B |
| Rapid City, SD (8 branches) | 1 of 11 | 23.3% | $875.4M | $3.76B |
| Missoula, MT (3 branches) | 2 of 11 | 20.9% | $824.9M | $3.95B |
| Des Moines-West Des Moines, IA (11 branches) | 8 of 57 | 1.9% | $732.4M | $37.99B |
| Bozeman, MT (4 branches) | 3 of 16 | 13.2% | $689.8M | $5.24B |
| Kalispell, MT (7 branches) | 2 of 12 | 15.6% | $620.8M | $3.97B |
| Branch | Location | ZIP | Deposits |
|---|---|---|---|
| First Interstate Bank (main office) | Billings, MT | 59101 | $1.07B |
| Missoula Downtown Branch | Missoula, MT | 59802 | $599.8M |
| Sioux Falls Downtown Branch | Sioux Falls, SD | 57104 | $486.0M |
| Bend Downtown Branch | Bend, OR | 97703 | $389.4M |
| Casper Downtown Branch | Casper, WY | 82601 | $357.9M |
| Jackson Main Branch | Jackson, WY | 83001 | $350.0M |
| Riverton Branch | Riverton, WY | 82501 | $344.2M |
| Great Falls 10th Ave S Branch | Great Falls, MT | 59405 | $331.0M |
| Rapid City Gateway Branch | Rapid City, SD | 57701 | $326.7M |
| Clive University Ave. Branch | Clive, IA | 50325 | $324.1M |
| Laramie Downtown Branch | Laramie, WY | 82070 | $303.6M |
| Helena Gulch Branch | Helena, MT | 59601 | $277.8M |
| Omaha 93rd & W. Dodge Road Branch | Omaha, NE | 68114 | $269.1M |
| Bozeman West Branch | Bozeman, MT | 59718 | $264.3M |
| Sturgis Branch | Sturgis, SD | 57785 | $259.0M |
| Gillette Downtown Branch | Gillette, WY | 82716 | $253.8M |
| Sheridan Downtown Branch | Sheridan, WY | 82801 | $234.9M |
| Redmond Branch | Redmond, OR | 97756 | $217.8M |
| Billings Heights Branch | Billings, MT | 59105 | $214.9M |
| Bozeman Main Branch | Bozeman, MT | 59715 | $212.7M |
| Bellevue Galvin Rd. S. Branch | Bellevue, NE | 68005 | $197.1M |
| Billings Shiloh Branch | Billings, MT | 59102 | $191.9M |
| Kalispell Branch | Kalispell, MT | 59901 | $190.6M |
| Cheyenne Downtown Branch | Cheyenne, WY | 82001 | $189.1M |
| Livingston Branch | Livingston, MT | 59047 | $181.8M |
| Whitefish Branch | Whitefish, MT | 59937 | $179.5M |
| Polson Branch | Polson, MT | 59860 | $167.5M |
| Boise West Myrtle Branch | Boise, ID | 83702 | $166.0M |
| Spearfish Main Branch | Spearfish, SD | 57783 | $161.1M |
| Miles City Branch | Miles City, MT | 59301 | $159.7M |
| Coeur D'Alene Riverstone Branch | Coeur D Alene, ID | 83814 | $157.8M |
| Watertown Uptown Branch | Watertown, SD | 57201 | $150.5M |
| Nampa 12th Branch | Nampa, ID | 83651 | $149.8M |
| Aberdeen West Branch | Aberdeen, SD | 57401 | $144.0M |
| Altoona Branch | Altoona, IA | 50009 | $143.3M |
| Bend Third & Revere Branch | Bend, OR | 97701 | $138.0M |
| Spokane Downtown Branch | Spokane, WA | 99201 | $136.7M |
| Missoula South Branch | Missoula, MT | 59801 | $133.7M |
| Meridian East Broadway Branch | Meridian, ID | 83642 | $132.2M |
| Casper Mills Branch | Mills, WY | 82644 | $130.3M |
| Hayden Branch | Coeur D Alene, ID | 83815 | $127.9M |
| Boise 9th St Branch | Boise, ID | 83702 | $124.8M |
| Colstrip Branch | Colstrip, MT | 59323 | $122.8M |
| Eagle Branch | Eagle, ID | 83616 | $121.9M |
| Fort Dodge Downtown Branch | Fort Dodge, IA | 50501 | $118.6M |
| Lander Branch | Lander, WY | 82520 | $114.5M |
| Burlington N. Roosevelt Ave. Branch | Burlington, IA | 52601 | $113.9M |
| Caldwell Kimball Branch | Caldwell, ID | 83605 | $112.6M |
| Great Falls West Branch | Great Falls, MT | 59404 | $112.5M |
| Helena Capital Branch | Helena, MT | 59601 | $110.8M |
| Billings West Branch | Billings, MT | 59102 | $109.2M |
| Buffalo Branch | Buffalo, WY | 82834 | $108.0M |
| Belgrade Branch | Belgrade, MT | 59714 | $107.1M |
| Marshalltown Downtown Branch | Marshalltown, IA | 50158 | $106.8M |
| Billings Grand Branch | Billings, MT | 59102 | $106.1M |
| Bozeman Gallatin Center Branch | Bozeman, MT | 59718 | $105.7M |
| Grants Pass North Branch | Grants Pass, OR | 97526 | $103.9M |
| Medford Biddle Road Branch | Medford, OR | 97504 | $103.7M |
| Dell Rapids Branch | Dell Rapids, SD | 57022 | $103.4M |
| Spokane Northside Branch | Spokane, WA | 99205 | $102.4M |
| Gillette South Branch | Gillette, WY | 82718 | $102.4M |
| Prineville Branch | Prineville, OR | 97754 | $99.5M |
| Hood River Branch | Hood River, OR | 97031 | $97.4M |
| Bend East Forum Branch | Bend, OR | 97701 | $94.6M |
| Hardin Branch | Hardin, MT | 59034 | $94.5M |
| Lincoln Cotner Blvd. Branch | Lincoln, NE | 68505 | $94.5M |
| Lexington Downtown Branch | Lexington, NE | 68850 | $94.5M |
| Sheridan Sugarland Branch | Sheridan, WY | 82801 | $93.8M |
| Denver Cherry Creek Branch | Denver, CO | 80206 | $92.6M |
| Casper East Branch | Casper, WY | 82609 | $92.4M |
| Missoula North Reserve Branch | Missoula, MT | 59808 | $91.3M |
| Belle Fourche Branch | Belle Fourche, SD | 57717 | $91.0M |
| Post Falls Branch | Post Falls, ID | 83854 | $88.6M |
| Custer Branch | Custer, SD | 57730 | $86.9M |
| Red Lodge Branch | Red Lodge, MT | 59068 | $86.4M |
| Omaha West L. St. Branch | Omaha, NE | 68137 | $86.2M |
| Grants Pass South Branch | Grants Pass, OR | 97527 | $85.7M |
| Sisters Branch | Sisters, OR | 97759 | $85.4M |
| Lincoln Downtown Branch | Lincoln, NE | 68508 | $83.3M |
| Wall Branch | Wall, SD | 57790 | $83.0M |
| Sunriver Branch | Bend, OR | 97707 | $82.2M |
| Bigfork Branch | Bigfork, MT | 59911 | $81.8M |
| Hamilton Branch | Hamilton, MT | 59840 | $81.4M |
| Mountain Home Branch | Mountain Home, ID | 83647 | $80.6M |
| Ames S. Duff Ave. Branch | Ames, IA | 50010 | $79.7M |
| Milbank Branch | Milbank, SD | 57252 | $79.2M |
| Helena North Branch | Helena, MT | 59602 | $77.2M |
| Internet Bank Branch | Billings, MT | 59101 | $77.2M |
| Emmett Branch | Emmett, ID | 83617 | $77.1M |
| Hot Springs Branch | Hot Springs, SD | 57747 | $75.9M |
| Hastings Branch | Hastings, NE | 68901 | $75.9M |
| North Platte Branch | North Platte, NE | 69101 | $75.8M |
| Omaha S. 84th St Branch | Omaha, NE | 68127 | $75.2M |
| Deadwood Branch | Deadwood, SD | 57732 | $74.7M |
| Sioux Falls S. Cliff Ave. Branch | Sioux Falls, SD | 57103 | $72.6M |
| Boulder 9th St. Branch | Boulder, CO | 80302 | $71.1M |
| Great Falls Downtown Branch | Great Falls, MT | 59401 | $69.3M |
| Bend South Branch | Bend, OR | 97702 | $69.2M |
| Portland 200 Market Branch | Portland, OR | 97201 | $68.3M |
| Madison Branch | Madison, SD | 57042 | $67.5M |
Source: FDIC Summary of Deposits, June 30, 2026. How the survey works.
Regulator records: FDIC BankFind (cert 1105) · FFIEC NIC profile (RSSD 659855)