Idaho Freestone
Big Lost River Fishing Report, Flows and Hatches
A high-desert freestone below Mackay Reservoir where sight-nymphing to rainbows pushing 25 inches is the draw. It runs catch-and-release from December through the Friday before Memorial Day.
Freestone
Idaho
5,950 ft
Gauge 13127000
Right now
Live conditions
The hatch chart
Big Lost River hatch chart
The emergences that come off the Big Lost by month, straight from the Rivus hatch model.
| Hatch | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Midge Midge, #18-24 | ||||||||||||
Blue Winged Olive Mayfly, #14-18 | ||||||||||||
Crane Fly Crane Fly, #10-14 | ||||||||||||
Little Yellow Sally Stonefly, #12-14 | ||||||||||||
Caddisfly Caddis, #14-18 | ||||||||||||
Pale Morning Dun Mayfly, #14-18 | ||||||||||||
Salmonfly Stonefly, #4-8 | ||||||||||||
Golden Stonefly Stonefly, #6-10 | ||||||||||||
Grasshopper / Terrestrial Hopper, #8-12 | ||||||||||||
Mahogany Dun Mayfly, #14-16 |
How it fishes
A Idaho freestone
A freestone river runs free off snowmelt and rain, so it swings hard with the seasons. It blows out and browns up in spring runoff, then drops and warms into summer. The hatches track the water temperature more than the calendar, so you time your trip to the flow and the thermometer.
Flow and gauge
Reading the flows
The Big Lost is metered at USGS gauge 13127000. Watch the trend as much as the number: a river that is dropping and clearing fishes very differently from one that is coming up.
Access and regulations
Before you fish
Access and the right to fish are the angler’s responsibility, every time. Public access, private water, and seasonal closures vary along the river, so confirm where you can legally stand and wade before you go. We do not point you to a specific spot.
Read the current rules, license requirements, and any special-regulation water before you go. Regulations change season to season, so check them fresh.
Flow and water temperature from USGS, weather from NWS and NOAA, refreshed hourly. Real-time USGS readings are provisional and subject to revision. The hatch chart and river read are Rivus model output.