Yellowtail Afterbay Reservoir trout stocking
Montana · lake
Yellowtail Afterbay Reservoir was last stocked 5 months ago (May 6, 2026). We have 3 stockings on record since Apr 1, 2025, 1 in the last 12 months (6,239 fish). Most stockings come in April. Species stocked: rainbow trout.
River conditions
USGS gage: Bighorn R bl Yellowtail Afterbay Dam nr St. Xavier (2 km away).
- Flow
- 1,800 cfs
- about normal for the last six weeks
- Gage height
- 60.46 ft
Latest reading Sep 25, 2026, 3:15 AM UTC. USGS data are provisional. Gage page at USGS.
Weather at Yellowtail Afterbay Reservoir
- Tonight54°FMostly Clearwind 8 mph
- Friday84°FPartly Sunnywind 5 to 9 mph
- Friday Night50°FPartly Cloudywind 6 to 17 mph
- Saturday74°FSunnywind 5 to 12 mph
- Saturday Night46°FPartly Cloudy1% rain · wind 2 to 10 mph
- Sunday68°FPartly Sunny13% rain · wind 2 to 7 mph
Forecast from the National Weather Service for this location, refreshed hourly.
When is Yellowtail Afterbay Reservoir stocked?
Most stockings come in April.
By month, all years
Year by year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 1 | |||||||||||
| 2025 | 2 |
What is stocked
| Species | Stockings | Fish | Fish per stocking | Typical size |
|---|---|---|---|---|
| Rainbow trout | 3 | 21,199 | 7,066 | 4.5 in |
Stocking history
| Date | Species | Fish | Pounds | Hatchery |
|---|---|---|---|---|
| May 6, 2026 | Rainbow trout | 6,239 | Bluewater Springs Trout Hatchery | |
| Apr 2, 2025 | Rainbow trout | 6,649 | Bluewater Springs Trout Hatchery | |
| Apr 1, 2025 | Rainbow trout | 8,311 | Bluewater Springs Trout Hatchery |
From Montana fish and wildlife agency reports, collected nightly and kept after the agency takes them down. Agencies revise reports; check the agency's report before you go.
Where is Yellowtail Afterbay Reservoir?
Montana. The marker is the agency's location for this water; streams are often stocked at several access points.
Questions about Yellowtail Afterbay Reservoir
- When was Yellowtail Afterbay Reservoir last stocked?
- The latest reported stocking was May 6, 2026 (rainbow trout, 6,239 fish), according to Montana agency reports.
- How often is Yellowtail Afterbay Reservoir stocked?
- It was stocked 1 times in the last 12 months. Across all years on record, most stockings come in April.
- What kind of trout are stocked in Yellowtail Afterbay Reservoir?
- Rainbow trout (3 stockings, 21,199 fish).