GREAT FALLS — Residents of Fort Shaw, Sun River, and Simms are urged to use caution as rain continues to create near-flood conditions in some areas. Additional rain is expected through Monday, which may lead to rising water levels, water over roadways, and localized flooding.
The Cascade County Sheriff's Office said that deputies and Cascade County Disaster & Emergency Services are monitoring conditions.
If you encounter flooded roads, you are urged to turn around and find an alternate route. Never drive through standing water, as conditions beneath the surface may be unsafe.
Cascade County DES provided the following information:
- Sun River near Simms is measuring just under 6 feet as of 8:45pm on 5/30/2026 (5.99ft). This means the river is just below bank breach.
- Ulm Vaughn Fishing Access: Water levels are approximately 2 feet before water crests at lowest point, approximately 5 feet at highest point at this access.
- Largent Bend Fishing Access: Water levels are approximately 2 feet before water crests at lowest point, approximately 4 feet at highest point at this access.
- Medicine River Fishing Access, Sun River: Water has already crested onto road. There are nearby houses, approximately 1.5 feet before water crests onto the residential areas.
From the National Weather Service in Great Falls:
FLOOD ADVISORY IN EFFECT UNTIL MIDNIGHT TONIGHT
* WHAT...Minor flooding in areas of poor drainage and elevated streamflows are expected.
* WHERE...Portions of central, north central, and west central Montana, including the following counties, in central Montana, Cascade. In north central Montana, Glacier, Pondera, Teton and Toole. In west central Montana, Lewis and Clark.
* WHEN...Until midnight MDT tonight.
* IMPACTS...Minor flooding in urban and rural areas of poor drainage. Some river and stream levels are elevated and will see additional rises to around bankful.
* ADDITIONAL DETAILS... - At 1022 AM MDT, Moderate to heavy rainfall accumulations of 1 to 2 inches have occurred across the advisory area over the last 24 hours, leading to elevated flow on some creeks and rivers and ponding of water in areas with poor drainage. - Additional rainfall amounts of 0.2 to 0.5 inches are expected at lower elevations through this evening with up to 1 inch of additional rainfall across areas near GLacier National Park and the Little Belt and Highwood Mountains. - Some locations that may experience minor flooding from elevated stream flow include... Some creeks originating in the Highwood and Little Belt Mountains. The Marias and St. Mary Rivers and tributaries in Glacier county including Badger Creek, Two-medicine River and Cut Bank Creek. - Additionally, the Sun river will remain at elevated levels and is forecast to remain just under bankful through Monday.
There are also flood advisories in Glacier County, Pondera County, Teton County, Toole County, and Valley County. Click here for more information.
