Mammoth Creek (Iron County) fishing
Mammoth Creek was last stocked on June 4, 2025 with 1,000 tiger trout (3.4 in. average), according to the Utah DWR fish stocking report. It is a river or stream in Iron County, Utah. From 2021 to 2026, DWR stocked 46,477 fish here, the 4th most of 23 stocked waters in Iron County.
Mammoth Creek stocking report, last 12 months
No stocking recorded in the last 12 months. The most recent record is dated June 4, 2025.
Source: Utah DWR fish stocking report. Stocking data fetched Sept. 25, 2026; newest record dated Sept. 23, 2026. DWR posts stockings after they happen and does not publish schedules.
When is Mammoth Creek stocked?
Based on DWR stocking records, 2021 to 2025. Stocked in 4 of those 5 years.
2025 stocking: 2 records, first on May 21, last on June 4.
In past years, stocking here had usually started by this time of year (4 of the last 5 years). No stocking has been recorded here yet in 2026.
DWR does not publish stocking schedules. Patterns are based on past stocking records and are not a promise of future stocking. Weather, water conditions and hatchery supply change plans. How we read patterns.
Mammoth Creek stocking profile
- First record in the DWR report: June 15, 2021. Since then DWR has logged 10 stockings here in 4 different years, 46,477 fish in all.
- Species stocked 2021 to 2026, by share of fish: cutthroat trout 87% (40,635 fish) and tiger trout 13% (5,842 fish).
- Busiest months in the record: June (30% of records) and September (30% of records).
- Stocked fish averaged 2.8 in. from 2021 to 2026 (per-record averages ranged from 1.7 to 10.2 in.). The yearly average was 3.1 in. in 2021 and 6.7 in. in 2025.
- Fish stocked 2021 to 2026: 46,477, the 4th most of 23 stocked waters in Iron County and 119th of 1,068 statewide.
- Nearest other water with a page: Louder Ranger Station, 1.1 mi away.
- Other water with this name: Mammoth Creek in Garfield County, 8 mi away. DWR lists them as separate waters (DWR water ids VIAA780-04 and VIAA780-03).
Computed from Utah DWR stocking records (fish counts and average lengths as DWR reports them). Past stocking is history, not a schedule.
Mammoth Creek stocking history by year
| Year | Records | Fish | Avg. length | Species |
|---|---|---|---|---|
| 2025 | 2 | 2,020 | 6.7 in. | Tiger trout |
| 2023 | 1 | 8,066 | 1.9 in. | Cutthroat trout |
| 2022 | 2 | 12,871 | 2.3 in. | Cutthroat trout, Tiger trout |
| 2021 | 5 | 23,520 | 3.1 in. | Cutthroat trout, Tiger trout |
All stocking records 2021 to Sept. 24, 2025 (10)
| June 4, 2025 | Tiger trout | 1,000 | 3.4 in. |
| May 21, 2025 | Tiger trout | 1,020 | 9.9 in. |
| Sept. 11, 2023 | Cutthroat trout | 8,066 | 1.9 in. |
| Sept. 12, 2022 | Cutthroat trout | 12,359 | 2.0 in. |
| June 15, 2022 | Tiger trout | 512 | 8.7 in. |
| Sept. 16, 2021 | Cutthroat trout | 9,250 | 2.3 in. |
| Aug. 18, 2021 | Cutthroat trout | 10,960 | 1.7 in. |
| July 13, 2021 | Tiger trout | 1,449 | 9.8 in. |
| July 1, 2021 | Tiger trout | 1,557 | 9.5 in. |
| June 15, 2021 | Tiger trout | 304 | 10.2 in. |
Fishing rules
The 2026 Utah Fishing Guidebook lists no water-specific rules for Mammoth Creek under that name, so statewide rules apply unless DWR posts a change. Some waters are covered by a group entry (for example a drainage or its tributaries).
Rules summarized in our own words from the 2026 Utah Fishing Guidebook. DWR can change rules mid-year: check the current guidebook and its updates at wildlife.utah.gov/guidebooks before fishing. See statewide limits.
Email me when Mammoth Creek is stocked
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"Was stocked" alerts come from new rows in the DWR stocking report. "Often stocked around now" heads-ups come from past stocking records only. DWR does not publish stocking schedules, so a heads-up is never a promise. We store your email only for these alerts; ask us to delete it at [email protected]. Privacy.
Mammoth Creek questions
When is Mammoth Creek stocked?
DWR does not publish stocking schedules. Past records show Mammoth Creek was stocked in early to mid June (3 of the last 5 years) and mid September (3 of the last 5 years). The most recent stocking in the DWR report is dated June 4, 2025.
What fish are in Mammoth Creek?
Since 2021 DWR has stocked tiger trout and cutthroat trout.
What are the fishing limits at Mammoth Creek?
The 2026 guidebook lists no water-specific rules under this name, so statewide limits apply unless DWR posts a change. See our statewide limits page and check the guidebook.
Stocking: Utah DWR fish stocking report, fetched Sept. 25, 2026. Location: Utah DWR, USGS NHD. Rules: 2026 Utah Fishing Guidebook. Page built Sept. 24, 2026. Found an error? [email protected]. Verify rules with DWR before fishing.