Flow range for best boatability uncertain. Please help your fellow boaters with a comment or report.
The first rapid of this reach is made up of 3 channels. Scouting from land is almost impossible, especially due to the US/Canada border dividing the river. Line up for the channel you want at the bridge, as crossing between them quickly becomes difficult. The farthest left, and the center channel, are class 4+ and appear to need at least 2,000 cfs to run at all. Both are short and steep with a decent final drop. River right channel is flatter and longer, and quite bony below 1,700 cfs, but runnable. Between 1,700-2,200 this channel is probably a stout class 3, but quickly moves to class 4 around 2,200 cfs.
At higher flows, the center channel appears to have dangerous holes. The river right channel is powerful class 3+ to 4 at 9,000 cfs.
ALL CHANNELS CONTAIN OLD DAM PILINGS AND METAL - SWIM CAREFULLY.