First Interstate Bank 302 branches across 14 states · $23.02B deposits

Branch network of First Interstate Bank (FDIC cert 1105) as of June 30, 2025. Headquartered in Polson, Montana.

Total Branches
302
States
14
Total Deposits
$23.02B
Avg / Branch
$76.2M

Branches by state

StateBranches
South Dakota 46
Iowa 45
Nebraska 44
Montana 43
Oregon 33
Idaho 20
Colorado 19
Washington 17
Wyoming 15
Arizona 10
Missouri 6
Kansas 2
Minnesota 1
North Dakota 1

Top counties (by branch count)

CountyBranches
Ada County, ID 10
Minnehaha County, SD 10
Yellowstone County, MT 9
Deschutes County, OR 9
Spokane County, WA 8
Douglas County, NE 8
Flathead County, MT 7
Pennington County, SD 7
Lancaster County, NE 7
Boulder County, CO 6
About the institution. First Interstate Bank is identified by FDIC certificate number 1105. The headquarters address shown (49573 Us Highway 93, Polson, Montana) is the branch with the lowest internal unique number — typically the institution's main office. For multi-state institutions, this is its legal HQ, which may differ from the corporate brand's perceived home (e.g., several brands consolidate to a Delaware or Ohio charter).

BankBranches · every U.S. bank branch by county and institution · data from FDIC Summary of Deposits June 30, 2025 · built by Claude