First Interstate Bank holds $25.8B in total assets and has $21.7B in deposits across 138 counties in 31 ranked markets and 10 states. Its deposit footprint is broadly distributed: the top three counties (Yellowstone County, Montana, Deschutes County, Oregon, and Minnehaha County, South Dakota) hold 18% of its deposits, and Montana accounts for 28% of the total. It is among the top three banks by deposits in 53 of the 138 counties where it operates. Figures are from the FDIC Summary of Deposits as of June 30, 2026, and are refreshed once a year after the next survey is released, not quarterly.
Deposits by county
Data as of June 30, 2026 (FDIC Summary of Deposits)
| County | Deposits | County’s % of Bank’s Deposits | Bank’s % of County Deposits | Branches |
|---|---|---|---|---|
| Yellowstone County, MT | $1.8B | 8.4% | 24.6% | 10 |
| Deschutes County, OR | $1.1B | 5.2% | 22.5% | 9 |
| Minnehaha County, SD | $955M | 4.4% | 0.2% | 10 |
| Missoula County, MT | $825M | 3.8% | 20.9% | 3 |
| Ada County, ID | $803M | 3.7% | 5.0% | 10 |
| Gallatin County, MT | $690M | 3.2% | 13.2% | 4 |
| Douglas County, NE | $657M | 3.0% | 2.0% | 8 |
| Flathead County, MT | $621M | 2.9% | 15.6% | 7 |
| Pennington County, SD | $616M | 2.8% | 18.8% | 7 |
| Natrona County, WY | $581M | 2.7% | 22.4% | 3 |
| Polk County, IA | $531M | 2.4% | 1.7% | 5 |
| Cascade County, MT | $513M | 2.4% | 23.5% | 3 |
| Spokane County, WA | $508M | 2.3% | 4.8% | 8 |
| Lewis and Clark County, MT | $466M | 2.1% | 17.8% | 3 |
| Fremont County, WY | $459M | 2.1% | 44.1% | 2 |
| Kootenai County, ID | $431M | 2.0% | 8.1% | 5 |
| Teton County, WY | $381M | 1.8% | 13.7% | 2 |
| Campbell County, WY | $356M | 1.6% | 24.1% | 2 |
| Sheridan County, WY | $329M | 1.5% | 23.8% | 2 |
| Albany County, WY | $304M | 1.4% | 39.5% | 1 |
| Lawrence County, SD | $298M | 1.4% | 30.4% | 4 |
| Lancaster County, NE | $287M | 1.3% | 1.9% | 5 |
| Jackson County, OR | $277M | 1.3% | 6.2% | 5 |
| Canyon County, ID | $262M | 1.2% | 8.8% | 2 |
| Meade County, SD | $259M | 1.2% | 52.8% | 1 |
| Laramie County, WY | $256M | 1.2% | 8.0% | 2 |
| Boulder County, CO | $241M | 1.1% | 2.1% | 6 |
| Sarpy County, NE | $225M | 1.0% | 6.6% | 2 |
| Park County, MT | $223M | 1.0% | 38.0% | 2 |
| Josephine County, OR | $190M | 0.9% | 9.5% | 2 |
| Brown County, SD | $189M | 0.9% | 9.4% | 2 |
| Codington County, SD | $180M | 0.8% | 11.3% | 2 |
| Lake County, MT | $168M | 0.8% | 19.3% | 1 |
| Custer County, MT | $160M | 0.7% | 17.5% | 1 |
| Webster County, IA | $154M | 0.7% | 15.7% | 2 |
| Denver County, CO | $151M | 0.7% | 0.2% | 2 |
| Marshall County, IA | $148M | 0.7% | 10.6% | 2 |
| Story County, IA | $137M | 0.6% | 4.4% | 3 |
| Rosebud County, MT | $136M | 0.6% | 46.1% | 2 |
| Jasper County, IA | $117M | 0.5% | 13.1% | 3 |
| Larimer County, CO | $114M | 0.5% | 1.1% | 3 |
| Des Moines County, IA | $114M | 0.5% | 7.5% | 1 |
| Custer County, SD | $112M | 0.5% | 76.0% | 2 |
| Johnson County, WY | $108M | 0.5% | 16.3% | 1 |
| Weld County, CO | $101M | 0.5% | 1.6% | 2 |
| Crook County, OR | $99M | 0.5% | 25.9% | 1 |
| Hood River County, OR | $97M | 0.4% | 14.2% | 1 |
| Lane County, OR | $97M | 0.4% | 1.4% | 2 |
| Big Horn County, MT | $95M | 0.4% | 30.4% | 1 |
| Dawson County, NE | $94M | 0.4% | 6.2% | 2 |
| Butte County, SD | $91M | 0.4% | 26.7% | 1 |
| Carbon County, MT | $86M | 0.4% | 34.2% | 1 |
| Lincoln County, SD | $85M | 0.4% | <0.1% | 2 |
| Pottawattamie County, IA | $85M | 0.4% | 3.4% | 2 |
| Ravalli County, MT | $81M | 0.4% | 6.1% | 1 |
| Elmore County, ID | $81M | 0.4% | 27.6% | 1 |
| Grant County, SD | $79M | 0.4% | 19.7% | 1 |
| Douglas County, OR | $79M | 0.4% | 0.8% | 2 |
| Gem County, ID | $77M | 0.4% | 24.2% | 1 |
| El Paso County, CO | $76M | 0.4% | 0.7% | 2 |
| Fall River County, SD | $76M | 0.3% | 70.0% | 1 |
| Adams County, NE | $76M | 0.3% | 5.3% | 1 |
| Lincoln County, NE | $76M | 0.3% | 4.9% | 1 |
| Stillwater County, MT | $73M | 0.3% | 26.5% | 2 |
| Lincoln County, OR | $71M | 0.3% | 5.7% | 2 |
| Montgomery County, IA | $70M | 0.3% | 18.7% | 2 |
| Multnomah County, OR | $68M | 0.3% | 0.2% | 1 |
| Lake County, SD | $67M | 0.3% | 13.6% | 1 |
| Brule County, SD | $65M | 0.3% | 17.2% | 1 |
| Klamath County, OR | $64M | 0.3% | 6.1% | 1 |
| Fremont County, IA | $64M | 0.3% | 27.5% | 2 |
| Walworth County, SD | $61M | 0.3% | 13.3% | 1 |
| Marion County, OR | $59M | 0.3% | 0.9% | 1 |
| Wasco County, OR | $56M | 0.3% | 8.9% | 1 |
| Platte County, NE | $55M | 0.3% | 3.1% | 1 |
| Coos County, OR | $54M | 0.2% | 4.0% | 2 |
| Wayne County, IA | $54M | 0.2% | 27.4% | 2 |
| Potter County, SD | $52M | 0.2% | 24.9% | 1 |
| Glacier County, MT | $50M | 0.2% | 24.1% | 1 |
| Decatur County, IA | $49M | 0.2% | 24.7% | 1 |
| Worth County, MO | $47M | 0.2% | 100.0% | 1 |
| Madison County, MT | $46M | 0.2% | 15.2% | 1 |
| Hall County, NE | $46M | 0.2% | 1.5% | 1 |
| Arapahoe County, CO | $45M | 0.2% | 0.2% | 1 |
| Black Hawk County, IA | $45M | 0.2% | 1.7% | 2 |
| Poweshiek County, IA | $44M | 0.2% | 7.6% | 1 |
| Warren County, IA | $43M | 0.2% | 3.2% | 1 |
| Buffalo County, NE | $43M | 0.2% | 1.8% | 1 |
| Dallas County, IA | $41M | 0.2% | 1.6% | 2 |
| Payette County, ID | $39M | 0.2% | 7.4% | 1 |
| Clarke County, IA | $38M | 0.2% | 12.3% | 1 |
| Hutchinson County, SD | $38M | 0.2% | 7.6% | 1 |
| Pacific County, WA | $36M | 0.2% | 9.8% | 1 |
| Lincoln County, MT | $34M | 0.2% | 8.9% | 1 |
| Corson County, SD | $34M | 0.2% | 51.3% | 2 |
| Spink County, SD | $34M | 0.2% | 13.0% | 1 |
| Fremont County, CO | $34M | 0.2% | 4.4% | 1 |
| Clatsop County, OR | $34M | 0.2% | 4.3% | 1 |
| Phelps County, NE | $31M | 0.1% | 6.1% | 1 |
| Page County, IA | $31M | 0.1% | 4.6% | 2 |
| Gentry County, MO | $30M | 0.1% | 12.4% | 1 |
| Lucas County, IA | $30M | 0.1% | 17.2% | 1 |
| Yankton County, SD | $30M | 0.1% | 2.3% | 1 |
| Mercer County, MO | $30M | 0.1% | 33.4% | 1 |
| Roberts County, SD | $29M | 0.1% | 6.1% | 1 |
| Whitman County, WA | $29M | 0.1% | 3.3% | 2 |
| Ringgold County, IA | $28M | 0.1% | 20.3% | 1 |
| Davison County, SD | $28M | 0.1% | 2.4% | 1 |
| Brookings County, SD | $27M | 0.1% | 1.2% | 1 |
| Grays Harbor County, WA | $25M | 0.1% | 1.8% | 1 |
| Broomfield County, CO | $25M | 0.1% | 1.2% | 1 |
| Cass County, IA | $24M | 0.1% | 1.7% | 1 |
| Jefferson County, OR | $24M | 0.1% | 13.5% | 1 |
| Johnson County, IA | $23M | 0.1% | 0.5% | 1 |
| Klickitat County, WA | $23M | 0.1% | 5.3% | 1 |
| Tama County, IA | $21M | 0.1% | 5.1% | 1 |
| Jefferson County, CO | $21M | 0.1% | 0.1% | 1 |
| Richardson County, NE | $20M | 0.1% | 5.2% | 1 |
| Day County, SD | $20M | 0.1% | 8.9% | 1 |
| Saunders County, NE | $20M | 0.1% | 2.0% | 1 |
| Gage County, NE | $20M | 0.1% | 2.2% | 1 |
| Clackamas County, OR | $20M | 0.1% | 0.2% | 1 |
| Mills County, IA | $19M | 0.1% | 3.0% | 1 |
| Taylor County, IA | $18M | 0.1% | 8.0% | 1 |
| Sullivan County, MO | $18M | 0.1% | 8.8% | 1 |
| Linn County, IA | $18M | 0.1% | 0.2% | 1 |
| Dodge County, NE | $18M | 0.1% | 1.0% | 1 |
| Henry County, IA | $17M | 0.1% | 3.3% | 1 |
| Otoe County, NE | $16M | 0.1% | 2.7% | 1 |
| Union County, IA | $16M | 0.1% | 3.1% | 1 |
| Saline County, NE | $16M | 0.1% | 2.6% | 1 |
| King County, WA | $16M | 0.1% | <0.1% | 1 |
| Wahkiakum County, WA | $16M | 0.1% | 21.3% | 1 |
| Grant County, WA | $14M | 0.1% | 0.8% | 1 |
| Benton County, WA | $13M | 0.1% | 0.4% | 1 |
| Putnam County, MO | $13M | 0.1% | 5.1% | 1 |
| Harrison County, MO | $12M | 0.1% | 2.7% | 1 |
| Woodbury County, IA | $4M | <0.1% | 0.1% | 1 |
“Deposits (SOD)” are deposits as reported to the FDIC at branch level in the Summary of Deposits (SOD), June 30, 2026, and are nominal. They reflect where deposits are booked and may differ from the institution’s balance-sheet total. “County’s % of Bank’s Deposits” is this county’s share of the institution’s total SOD deposits; “Bank’s % of County Deposits” is this institution’s deposits as a percent of all deposits booked in that county. Counties within a Combined or Metropolitan Statistical Area link to their full profile; other counties are shown for completeness.
Browse all covered institutions in the bank directory or the banks headquartered in MT. All 293 markets and the 1,523 counties with a branch within a CSA or MSA are covered in the Market Intelligence resource. See the methodology for how each figure is built and when to expect updates, or the disclaimer for how this data should, and should not, be read.
First Interstate Bank is named on this page solely to describe publicly reported FDIC deposit data. Its appearance does not imply any affiliation between First Interstate Bank and The Executive Recruiter Group, or endorsement by either.