Union Reservoir trout stocking
Weld County, Colorado · lake · 4,957 ft elevation
Union Reservoir was last stocked 4 months ago (Jun 5 to 11, 2026). We have 12 stockings on record since Sep 22, 2015, 1 in the last 12 months. Most stockings come in April.
- Number 10 of 13 stocked waters in Weld County by stocking days.
- Stocked about as often as a typical Colorado water on our record.
River conditions
Nearest USGS gage: ST VRAIN CR BLW BOULDER CR AT HWY 119 NR LONGMONT (4 km away, on a different stream or lake).
- Flow
- 37 cfs
- about normal for the last six weeks
- Gage height
- 9.59 ft
Latest reading Sep 29, 2026, 3:00 AM UTC. USGS data are provisional. Gage page at USGS.
Weather at Union Reservoir
- Tonight56°FChance Rain Showers32% rain · wind 5 mph
- Tuesday69°FChance Rain Showers29% rain · wind 2 to 7 mph
- Tuesday Night54°FChance Rain Showers50% rain · wind 6 mph
- Wednesday67°FChance Rain Showers54% rain · wind 6 to 10 mph
- Wednesday Night50°FChance Rain Showers47% rain · wind 7 to 10 mph
- Thursday67°FChance Rain Showers then Mostly Sunny35% rain · wind 8 mph
Forecast from the National Weather Service for this location, refreshed hourly.
When is Union 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 | 1 | |||||||||||
| 2024 | 1 | |||||||||||
| 2023 | 1 | |||||||||||
| 2022 | 1 | |||||||||||
| 2021 | 1 | |||||||||||
| 2020 | 1 | |||||||||||
| 2019 | 1 |
Stocking history
20261 stocking
| Date | Species | Since previous |
|---|---|---|
Week of Jun 5Latest Jun 5 to Jun 11 | Trout | 65 weeks |
20251 stocking
| Date | Species | Since previous |
|---|---|---|
Week of Mar 7 Mar 7 to Mar 13 | Trout | 374 days |
20241 stocking
| Date | Species | Since previous |
|---|---|---|
Week of Feb 27 Feb 27 to Mar 4 | Trout | 326 days |
20231 stocking
- Week of Apr 7 trout
20221 stocking
- Week of Apr 15 trout
20211 stocking
- Week of May 18 trout
20201 stocking
- Week of Apr 14 trout
20191 stocking
- Week of Mar 18 trout
20172 stockings
- Week of May 9 trout
- Week of Apr 4 trout
20161 stocking
- Week of Nov 8 trout
20151 stocking
- Week of Sep 22 trout
From Colorado 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. Seasons and limits: Colorado fishing regulations.
Where is Union Reservoir?
Weld County, Colorado. The marker is the agency's location for this water; streams are often stocked at several access points.
Stocked waters near Union Reservoir
- St Vrain State Park3 mistocked Nov 9, 2015
- Izaak Walton Longmont Pondpond · 4 mistocked Oct 3, 2025
- Milavec Reservoirlake · 6 mistocked Mar 13, 2026
- Lagerman Reservoirlake · 9 mistocked Jun 5, 2026
- McCall Lakelake · 9 mistocked Jun 5, 2026
- Roberts Lakelake · 9 mistocked Feb 26, 2026
- Thomas Reservoirlake · 11 mistocked May 22, 2026
- Johnstown Reservoirlake · 11 mistocked May 2, 2025
All stocked waters in Weld CountyStocked this week in Colorado
Questions about Union Reservoir
- When was Union Reservoir last stocked?
- The latest reported stocking was Jun 5 to 11, 2026, according to Colorado agency reports.
- How often is Union Reservoir stocked?
- It was stocked 1 times in the last 12 months. Across all years on record, most stockings come in April.
- Is Union Reservoir stocked often?
- Number 10 of 13 stocked waters in Weld County by stocking days. Stocked about as often as a typical Colorado water on our record. We count each day the agency reported stocking it.
Stocking report from Colorado Parks and Wildlife, which lists the waters stocked with catchable trout (about 10 inches) in the week before each report. Locations from the Colorado Fishing Atlas.