Montana Fishing Reports ยท Yellowstone Country Region
The Boulder runs north from the Absarokas to Big Timber, a beautiful freestone river with browns, rainbows and limited public access.
Looking for the latest Boulder River report? This page is updated by the AvidMax fly shop team with live flows, current conditions, hatches and the flies working now on the Boulder River โ Big Timber.
Current flows
Wind forecast
Boulder River fishing report
Updated November 7, 2026.
The gauge at Big Timber reads around 120 cfs, low and clear.
Small nymphs in the deeper runs and pockets.
Load your fly box
Before you head to Big Timber, bring: Pheasant Tail Nymph #16-18, Zebra Midge #18-20, Pat', s Rubber Legs #10, Parachute Adams #16-18, RS2 Emerger #18-22, JuJu Baetis #18-22, Black Beauty #20-24, Egg #14-16, Squirmy Wormie #12-14, Scud Bomb #14-16.
Flies working right now
The flies above that we have in stock right now.
Boulder River details
| Access | Fishing access sites near Big Timber and national forest water up the Main Boulder Road. |
|---|---|
| Elevation | About 4,100 to 5,500 ft |
| Nearest town | Big Timber, Montana |
| Best season | Summer and fall |
| Fish | Brown and rainbow trout |
| Regulations | Montana's stream regulations vary by district and river. Check Montana Fish, Wildlife and Parks regulations for the current rules. A Montana fishing license is required for anglers 12 and older. |
| Leaders and tippet | 9 ft leaders, 5X tippet |
| Camping | Custer Gallatin National Forest campgrounds up the Boulder |
| Kids | Partly. |
| Good to know | Much of the lower river is private. |
Fishing by season
Winter
Cold.
Spring
Runoff.
Summer
Caddis and hoppers.
Fall
Low water.
How to get there
From I-90 at Big Timber, take State Highway 298 south along the Boulder.