Upper Missouri Breaks planning
Upper Missouri Breaks wildlife & seasons
What lives here and what each season brings, so you time the trip for the experience you want.
Wildlife
The largest bighorn sheep herd in the lower 48, plus elk, mule deer, bald eagles and — below Judith Landing — growing numbers of bears.
Season by season
| Season | Window | Conditions |
|---|---|---|
| Spring | May – June | High, silty snowmelt water and fast flows; daytime highs in the 50s–60s. |
| Summer | July – August | Intense heat (90–100°F+), falling water and afternoon thunderstorms. |
| Autumn | September – October | Stable weather, clear skies and cool nights — a favorite window. |
| Winter | November – April | The river can freeze; sub-zero temperatures and wind make travel dangerous. |
Water conditions
The Missouri runs heavily silted. Settle the sediment with alum before filtering, or carry all your drinking water from the launch. Check BLM flow advisories before committing.