Fly Fishing in Montana
77 Montana streams have trout recorded in state fisheries surveys. A survey record means trout were caught there — it is not the same as a state classification of natural reproduction, which Montana does not publish. Current conditions shown where a USGS gauge covers the water.
Readings as of Aug 1, 2026, 6:49 PM UTC.
Trout Streams in Montana
Ranked by how many trout species state surveys have recorded. A survey record proves the fish were caught there, not that they reproduce there.
| # | Stream | County | Evidence | Trout species | Public | Water temp |
|---|---|---|---|---|---|---|
| 1 | Rock Creek | — | Recorded in surveys | Arctic Grayling, Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Tiger Trout(Brook X Brown hybrid), Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | 62.8°F |
| 2 | Beaver Creek | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout | — | — |
| 3 | Boulder Creek | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Cutthroat Trout, Rainbow Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | — |
| 4 | Mill Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Bull Trout, Cutthroat Trout, Rainbow Trout, Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | 63°F |
| 5 | Willow Creek | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Cutthroat Trout, Rainbow Trout, Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout | — | 68.5°F |
| 6 | Big Hole River | — | Recorded in surveys | Arctic Grayling, Brook Trout, Brown Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout | — | 72.5°F |
| 7 | Bitterroot River | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Tiger Trout(Brook X Brown hybrid), Westslope Cutthroat Trout | — | 68.7°F |
| 8 | Kootenai River | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | — |
| 9 | Madison River | — | Recorded in surveys | Arctic Grayling, Brook Trout, Brown Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | 73.6°F |
| 10 | Prospect Creek | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Rainbow Trout, Trout, Trout/Salmon, Westslope Cutthroat Trout | — | — |
| 11 | Red Rock Creek | — | Recorded in surveys | Arctic Grayling, Brook Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | 60.6°F |
| 12 | Warm Springs Creek | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Trout, Westslope Cutthroat Trout | — | 61.2°F |
| 13 | Blackfoot River | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Cutthroat Trout, Rainbow Trout, Westslope Cutthroat Trout | — | 66.2°F |
| 14 | Clear Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Cutthroat Trout, Rainbow Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | — |
| 15 | Gallatin River | — | Recorded in surveys | Arctic Grayling, Brook Trout, Brown Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | 69.6°F |
| 16 | North Fork Blackfoot River | — | Recorded in surveys | Brook Trout, Brown Trout, Bull Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Tiger Trout(Brook X Brown hybrid), Westslope Cutthroat Trout | — | 54.5°F |
| 17 | Stillwater River | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Rainbow Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout | — | 65.7°F |
| 18 | West Fork Bitterroot River | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Brown Trout, Bull Trout, Rainbow Trout, Trout, Westslope Cutthroat Trout | — | — |
| 19 | Beaverhead River | — | Recorded in surveys | Arctic Grayling, Brook Trout, Brown Trout, Rainbow Trout, Westslope Cutthroat Trout, Yellowstone Cutthroat Trout | — | 70.7°F |
| 20 | Flathead River | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Bull Trout, Lake Trout, Rainbow Trout, Westslope Cutthroat Trout | — | 75.7°F |
| 21 | Flint Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Bull Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | — |
| 22 | Judith River | — | Recorded in surveys | Brook Trout, Brown Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | — |
| 23 | Mission Creek | — | Recorded in surveys | Brown Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | — |
| 24 | Missouri River | — | Recorded in surveys | Brook Trout, Brown Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | 77.7°F |
| 25 | Ruby River | — | Recorded in surveys | Arctic Grayling, Brook Trout, Brown Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | 69.8°F |
| 26 | Shields River | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | 58.3°F |
| 27 | Smith River | — | Recorded in surveys | Brook Trout, Brown Trout, Cutthroat Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | 70.2°F |
| 28 | Thompson River | — | Recorded in surveys | Brook Trout, Brown Trout, Bull Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | — |
| 29 | Yellowstone River | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Yellowstone Cutthroat Trout, Yellowstone Cutthroat Trout X Rainbow | — | 75.7°F |
| 30 | Belt Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Westslope Cutthroat Trout | — | — |
| 31 | Big Spring Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Bull Trout, Rainbow Trout, Westslope Cutthroat Trout | — | — |
| 32 | Boulder River | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Yellowstone Cutthroat Trout | — | — |
| 33 | East Boulder River | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Rainbow X Cutthroat Trout, Yellowstone Cutthroat Trout | — | — |
| 34 | Jefferson River | — | Recorded in surveys | Arctic Grayling, Brook Trout, Brown Trout, Rainbow Trout, Westslope Cutthroat Trout | — | 73.9°F |
| 35 | Lost Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Bull Trout, Cutthroat Trout, Westslope Cutthroat Trout | — | 68.9°F |
| 36 | Middle Fork Rock Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Bull Trout, Trout, Westslope Cutthroat Trout | — | — |
| 37 | Red Rock River | — | Recorded in surveys | Brook Trout, Brown Trout, Cutthroat Trout, Rainbow Trout, Westslope Cutthroat Trout | — | — |
| 38 | Swan River | — | Recorded in surveys | Brook Trout, Brook X Bull Trout hybrid, Bull Trout, Rainbow Trout, Westslope Cutthroat Trout | — | — |
| 39 | Bighorn River | — | Recorded in surveys | Brown Trout, Rainbow Trout, Trout, Yellowstone Cutthroat Trout | — | 54.7°F |
| 40 | Clarks Fork Yellowstone River | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Yellowstone Cutthroat Trout | — | — |
| 41 | Fisher River | — | Recorded in surveys | Brook Trout, Bull Trout, Rainbow Trout, Westslope Cutthroat Trout | — | — |
| 42 | Hyalite Creek | — | Recorded in surveys | Arctic Grayling, Brown Trout, Rainbow Trout, Yellowstone Cutthroat Trout | — | — |
| 43 | Lake Creek | — | Recorded in surveys | Brook Trout, Bull Trout, Rainbow Trout, Westslope Cutthroat Trout | — | — |
| 44 | Musselshell River | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Yellowstone Cutthroat Trout | — | — |
| 45 | Silver Bow Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Westslope Cutthroat Trout | — | 71.4°F |
| 46 | Tenmile Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout, Westslope Cutthroat Trout | — | — |
| 47 | Blacktail Creek | — | Recorded in surveys | Brook Trout, Rainbow Trout, Westslope Cutthroat Trout | — | 57.9°F |
| 48 | Flatwillow Creek | — | Recorded in surveys | Brook Trout, Brown Trout, Rainbow Trout | — | — |
| 49 | Gardner River | — | Recorded in surveys | Brown Trout, Rainbow Trout, Yellowstone Cutthroat Trout X Rainbow | — | — |
| 50 | Little Blackfoot River | — | Recorded in surveys | Brook Trout, Brown Trout, Westslope Cutthroat Trout | — | — |
Montana River Flows
Largest current discharge, from USGS gauges.
| River | Flow (cfs) | Water temp | Measured |
|---|---|---|---|
| Clark Fork | 10,300 | 70.3°F | Aug 1, 2026, 5:45 PM UTC |
| Kootenai River | 9,040 | — | Aug 1, 2026, 6:00 PM UTC |
| Flathead River | 7,630 | 75.7°F | Aug 1, 2026, 5:30 PM UTC |
| Missouri River | 6,730 | 77.7°F | Aug 1, 2026, 6:00 PM UTC |
| Yellowstone River | 6,020 | 75.7°F | Aug 1, 2026, 5:45 PM UTC |
| South Fork Flathead River | 3,480 | 62.6°F | Aug 1, 2026, 5:45 PM UTC |
| Madison River | 3,430 | 73.6°F | Aug 1, 2026, 5:45 PM UTC |
| Bighorn River | 1,670 | 54.7°F | Aug 1, 2026, 6:30 PM UTC |
| Middle Fork Flathead River | 1,620 | 59.2°F | Aug 1, 2026, 5:45 PM UTC |
| North Fork Flathead River | 1,560 | 61.5°F | Aug 1, 2026, 5:45 PM UTC |
| Marias River | 1,060 | 73.6°F | Aug 1, 2026, 6:15 PM UTC |
| St Mary River | 1,050 | — | Aug 1, 2026, 6:15 PM UTC |
| Milk River | 1,030 | 79.3°F | Aug 1, 2026, 6:15 PM UTC |
| Blackfoot River | 900 | 66.2°F | Aug 1, 2026, 5:30 PM UTC |
| Swan River | 804 | — | Aug 1, 2026, 6:00 PM UTC |
| Stillwater River | 780 | 65.7°F | Aug 1, 2026, 6:15 PM UTC |
| Yellowstone River Fish Bypass Channel | 770 | 77.5°F | Aug 1, 2026, 6:00 PM UTC |
| Sun River | 762 | 73.4°F | Aug 1, 2026, 6:00 PM UTC |
| Clarks Fork Yellowstone River | 692 | — | Aug 1, 2026, 6:00 PM UTC |
| Bitterroot River | 638 | 68.7°F | Aug 1, 2026, 6:00 PM UTC |
Frequently Asked Questions
Which Montana streams hold trout?
77 Montana streams have trout on record from state fisheries surveys. Montana does not publish a wild-trout classification scheme the way Pennsylvania and Wisconsin do, so this reflects where trout were caught in surveys — presence, not documented natural reproduction. Rock Creek has the most trout species on record (13).
When is water too warm to fish in Montana?
Trout come under thermal stress above roughly 68°F and post-release mortality climbs sharply. Montana FWP restricts angling when max daily water temperature reaches 73F for 3 consecutive days. No Montana trout stream was above that threshold at the last reading. These are measurements, not advisories — check the state agency for restrictions actually in force.
Classification: state agency. Conditions: USGS NWIS (public domain).