Boulder Creek
Gorge
| Difficulty | IV-V |
| Length | 5.5 mi |
| Avg Gradient | n/a |
| Gauge | Yaak River Near Troy Mt |
| Flow Rate as of 1 hour | 2360 cfshigh runnable |
| Reach Info Last Updated | April 1, 2026 |
River Description
Boulder Creek is a too-often overlooked steep creek that enters the Kootenai River at the Montana/Idaho Border. The creek boasts one of the best 20-30 foot waterfalls in the region, Magnolia Falls.
Warm up rapids lead to a double ledge drop called Red Lobster as boaters enter into a gorge, more rapids lead to a tricky waterfall called Grunge Poser, and still more rapids lead to a walled-in gorge that culminates in an unrunnable waterfall.
THIS GORGE IS CLASS VI/UNRUNNABLE AND THERE IS ONLY ONE PORTAGE OPTION, THE FOLLOWING IS A DESCRIPTION OF HOW TO DO THE PORTAGE: After running Grunge Poser, the river begins a gradual right hand bend and starts to consolidate again. On the outside/river-left side at the apex of this bend is a gravel bar. Get out on this gravel bar, which is less than 200 yards below Grunge Poser. Downstream you will see the creek enter a vertical walled gorge. Head into the woods near the downstream end of the gravel bar, looking for the low point in the saddle. Go through the saddle and follow the path of least resistance into an ephemeral creek, and follow that creek downstream to where it confluences with Boulder Creek again. This portage around the gorge is easier than it has any right to be considering what is being walked around, but DO NOT PASS THAT GRAVEL BAR. Look in the gallery for a photo of the gravel bar.
A seal launch or rappel will drop you back into the creek just upstream of the classic Magnolia Falls. At low and moderate flows the falls offers an autoboof flake, but at high water you have to be a bit more creative to avoid a trip behind the curtain. If you walk magnolia be prepared for a short rappel on river left. Immediately below Magnolia Falls is a drop often portaged and then wind-down rapids before you reach the Kootenai River, at healthy flows they are pretty fun, at low water the neat rock walls are more memorable.
Access is via road from either Troy, MT or Bonners Ferry, ID, but the s
...River Features
Put In
Take Out
Trip Reports
Log in to add a reportWe paddled the run June 30, 2020 at 3.6' on the put in gage (Yaak was at about 730 cfs). The in between drops were low, and if that was all there was we would have called the run too low. However, wherever the creek channelized it was clean and the bedrock/named rapids were at a quality flow. There was wood in the pool above Magnolia, two from the group were able to climb onto the logs after being lowered into the pool in their boats and launch off them and ran the drop. The other two did throw and goes after portaging billy-goat style high on the left down to an obvious ledge 20-30' above the creek.
We boated this when the Yaak was at about 2,600. In between drops were fun, but the highlight bigger drops looked very intimidating. Also the ferry below Magnolia gets hairy. We opted for a longer portage instead of the ferry. IMO, this is a run best done with someone who's done it before and knows the logistics...don't miss the portage eddy. It's comes on a right turn only a couple minutes after leaving Grunge Poser.
No one in our group wanted a piece of this on that day