Montana fishing reports
45 reports for Montana — what's biting, water temps, and where to focus.
Spring trout window open on the Yellowstone ahead of peak runoff
Montana Fish, Wildlife & Parks has joined state health and environmental agencies in releasing PFAS fish consumption advisories for certain Montana waterbodies — per MT FWP Fishing News, anglers who regularly keep their catch should consult the current advisory list before their next outing. On the water, the Yellowstone River at Corwin Springs is recording 1,070 cfs as of May 10 (USGS gauge 06043500), a moderate pre-runoff flow that keeps the upper system accessible before peak snowmelt pushes levels significantly higher. Anglers heading to the Billings-area stretch should note that Grey Bear Fishing Access Site remains under partial closure — boat ramp and parking area restricted — with MT FWP targeting completion by May 21. No specific guide or tackle-shop bite reports for the Yellowstone or Missouri corridors surfaced in this week's feeds; conditions described here reflect typical early-May patterns for the region, with trout likely holding in moderate runs and inside bends as emerging hatches begin to build.
Flathead at Snowmelt Peaks: Edge-Water Cutthroat the Key Play
USGS gauge 12372000 clocked the Flathead drainage at 14,900 cfs and 52°F just before dawn on May 7 — textbook peak-runoff territory for early May in northwest Montana. Main-stem wading is effectively off the table at those flows, and drift anglers need to read seams carefully. The productive water right now is the soft stuff: eddy lines, tributary confluences, and slower inside bends where cutthroat and whitefish can stack without burning constant energy against the current. On the lake side, Flathead Lake's surface is warming through the low-50s, historically a transition window that draws lake trout shallower before summer thermoclines lock in. One Montana-specific note worth your attention: Flylords Mag reported this week that PFAS chemical contamination has been detected in fish across several of the state's most popular fisheries, with Montana PBS also alleging that Montana FWP suppressed a 2024 internal report on the findings. No fisheries are currently closed, but anglers keeping fish should check for updated consumption advisories before harvesting.
Yellowstone caddis hatches building ahead of runoff
USGS gauge 06043500 clocked the Yellowstone River at 771 cfs on May 7 — a fishable pre-runoff reading that opens a productive window before snowmelt pushes flows into spring flood territory. Hatch Magazine, drawing on decades of Yellowstone hatch expertise, flags that caddis emergences are ramping up and deserve anglers' full attention right now. On the access side, MT FWP Fishing News reports that the boat ramp and parking area at Grey Bear Fishing Access Site on the Yellowstone remain closed due to ongoing construction delays, with completion now expected around May 21 — plan your float access accordingly and consult myfwp.mt.gov/fwpPub/allRestrictions before any float trip. One significant health note: MT FWP, alongside DEQ and DPHHS, has released PFAS fish consumption advisories for certain Montana waterbodies; consult the state advisory before keeping any catch. Nymphing and emerging caddis dry-fly presentations are the techniques to lean on while these moderate flows hold.
Yellowstone at 740 cfs and Rising: Boat Ramp Closed, PFAS Advisory Issued
USGS gauge 06043500 recorded 740 cfs on the afternoon of May 6—building spring runoff that signals the Yellowstone's main stem may begin losing clarity in the days ahead. Anglers planning to float should know that the boat ramp and parking area at Grey Bear Fishing Access Site on the Yellowstone are currently restricted; MT FWP Fishing News confirms the construction project has been delayed and now runs through approximately May 21. Montana fish managers also released new PFAS fish consumption advisories this week: MT FWP Fishing News reports that some Montana waterbodies have detectable levels of PFAS contaminants, so verify the current advisory list before keeping fish for the table. No guide or tackle-shop bite reports were available for this update—species outlooks reflect gauge data, agency notices, and seasonal patterns typical for early May in this drainage. Hatch Magazine notes that caddis emergences are among the more productive early-season hatch windows in Yellowstone-area waters, worth scouting on clearer tailwater stretches.
Yellowstone at 710 cfs: Wade Window Open as Caddis Hatches Build
USGS gauge 06043500 is logging 710 cubic feet per second as of May 4 — a wade-friendly flow that keeps Montana's Yellowstone corridor fishable ahead of snowmelt runoff. Caddis emergences are the defining hatch event this month: Hatch Magazine's deep dive into Yellowstone hatches underscores that matching emergence timing is the key to dry-fly success in early May, with activity tracking closely to afternoon water temperatures. Anglers headed to the Yellowstone should plan around the ongoing construction project at Grey Bear Fishing Access Site, where MT FWP Fishing News reports the boat ramp and parking area closure has been extended — completion is now expected around May 21. MT FWP has also released PFAS fish consumption advisories for select Montana waterbodies; visit myfwp.mt.gov before keeping your catch. For anglers who want a voice in the future fishery, FWP is accepting public input on 41 proposed 2027–2028 regulation changes and hosting a Billings meeting May 11 at 6 p.m.
Flathead & Bitterroot Hit 51°F as Spring Flows Surge Past 15,000 cfs
USGS gauge 12372000 registered 15,000 cfs and a 51°F water temperature early Monday — classic early-May snowmelt conditions for northwest Montana. The 51°F reading puts water squarely in prime trout territory, though the high volume pushes fish off open midchannel runs and into softer pockets along cut banks and behind boulders. Hatch Magazine's spring coverage of caddis emergences signals that these insects are active and trout are keyed on subsurface pupae and soft-hackle wets in windows when clarity allows. Field & Stream's guide to aquatic insects for trout reinforces that midges, stoneflies, and caddis collectively define the spring feeding calendar right now. The waning gibbous moon extends low-light windows at first light and dusk — historically the best entry points during high-water conditions on Montana freestone systems. No local charter or shop intel was available this cycle; conditions are assessed from gauge data, seasonal norms, and regional reporting.
Yellowstone at 631 cfs: Pre-Runoff Trout Window Opens in Montana
With the Yellowstone River reading 631 cfs at USGS gauge 06043500 as of May 3, flows are on the moderate end for early May — a brief fishable window before snowmelt pushes the system into peak spring runoff. Water temperature data is unavailable from the gauge, but early May typically keeps this drainage in the 45–55°F range, cool enough to concentrate fish in seams and slower pools. Hatch Magazine's seasonal caddis emergence feature — which specifically references Yellowstone hatch patterns — notes that a working knowledge of aquatic insects meaningfully improves catch rates as hatches begin to ignite on warming afternoons. Field & Stream's aquatic insect primer this week covers all four trout-diet staples: mayflies, stoneflies, caddisflies, and midges, each relevant across both the Yellowstone and Missouri tailwater right now. MidCurrent's tying content highlights low-light nymph patterns and bottom-bouncing streamers for technical, pressured water — techniques that map directly to current Missouri River conditions.
Spring Runoff Peaks on Flathead & Bitterroot as Water Climbs to 51°F
USGS gauge 12372000 registered 15,000 cfs and 51°F on the morning of May 3 — the most concrete signal available for western Montana's current fishing conditions. Snowmelt from the surrounding ranges is driving flows well above normal, and the Bitterroot corridor is running bank-full, making wading dangerous on most stretches. At 51°F, however, water temperatures are solidly in the feeding range for rainbow and westslope cutthroat trout. No Montana-specific reporting appeared in this cycle's angler-intel feeds; the conditions below reflect the gauge data and typical early-May seasonal patterns for this region. Flathead Lake offers a better near-term option than the river: high tributary inflows are stirring the water column, but boat anglers working structure away from turbid inflows can target lake trout and bull trout in deeper water.
Yellowstone Running 590 CFS: Pre-Runoff Trout Window Is Open
USGS gauge 06043500 recorded 590 cfs on the Yellowstone drainage as of May 2 — a relatively modest flow for early May that signals we're still in the pre-runoff window. Water temperatures were unavailable from the gauge, but conditions typical for this period suggest river temps in the low-to-mid 40s°F, keeping trout active and holding near the bottom. Field & Stream's recent breakdown on aquatic insects highlights that mayflies, stoneflies, caddisflies, and midges form the core of a trout's diet — all four groups begin emerging at varying intensities across Montana streams in early May. No region-specific charter, shop, or agency reports reached our feeds this cycle, so we're working from gauge data and established seasonal patterns. The full moon on May 3 tends to shift prime feeding into low-light windows at dawn and dusk. Anglers targeting browns and rainbows should prioritize morning sessions before midday sun can spook fish in the clear, low-flow water that comes with pre-runoff conditions.