Imnaha, Oregon, US
|Usual Difficulty||III-IV (for normal flows)|
The 7 miles below the town of Imnaha is pretty flat flowing through ranch land (mainly class I and II with an ocasional class III move). The scenery picks up at Fence Creek where the road turns to dirt and this is probably your best put-in option. Below this point the scenery is stunning! The whitewater is mainly class II and III. After Cow Creek the river pick up a bit. Class II and III with a few class IV moves thrown in. No big rapids, mainly one move type scenarios. Lots of fun eddy catching moves in this strecth. Not too hard, but really fun. The hike back up to Cow Creek is not bad. Mostly flat with a few small uphill sections. Bring long pants for the hike due to poison ivy. The alternative is to continue on the Snake down to Heller Bar. If your are in the area, this run is well worth it for the stunning scenery alone. The fun somewhat technical whitewater is a bonus.
Some more info at http://mthoodh2o.blogspot.com/2011/09/starting-with-guidebook.html
The old gauge USGS for this section is no longer available.
NOAA has a gauge here: https://water.weather.gov/ahps2/hydrograph.php?wfo=pdt&gage=imno3
Here is some documentation of a trip at 550 cfs, which was reported to be a nice flow for the lower.
The headwaters section is good from 500-1500 cfs on that same gauge from snowmelt.
Please comment if you have information or datapoints to offer.
You can also check the cfs listing on the Idaho Power site.