American, Middle Fork - -1) Interbay Dam to Oxbow Reservoir

American, Middle Fork, California, US


-1) Interbay Dam to Oxbow Reservoir (End of the World)

Usual Difficulty IV-V (for normal flows)
Length 10.06 Miles
Avg. Gradient 128 fpm

General Character

General Character
Photo by Chris Tulley taken 05/17/11

River Description

Summary: This is great wilderness run. Good mix of boulder gardens and bedrock rapids. IV+ to V- in difficulty. First 3 miles of run are mostly high quality IV+ / V-. Then, gradient mellows and the next 4-5 miles slide away quickly with some occasional class IV to keep you on your toes. Then, you cash out on the gradient bank with the last ½ mile being the steepest of the run. The inconsistent gradient/difficulty keeps this run from being a classic. Most similar comparisons would be to Canyon creek (SF Yuba trib), SF T, and Lavazola. Predictable ideal flows (even simple gauge readings) would yield paddlers here on a regular basis.

Flow:  Currently the crux of End of the World is finding the right flow. American Whitewater is working to secure access to PCWA (Placer County Water Authority) gauges and hosted a flow study in 2010. Note: Based on the algae growth in the riverbed, it appears this run has boatable flows much more often than common wisdom in paddling circles would suggest.
·         Minimum = ~300 cfs at PI, ~400 by takeout
·         Medium = 500-600 at takeout
·         High = ???
One tributary (Mosquito creek) joins the run approx mi 2.5-3. In May of a big water year, this added about 30cfs.
Put-in: End of the World Power House, sometimes referred to as Interbay Dam (~2440’). Paved roads all the way. From the take out drive up Mosquito Ridge Road, then turn right on the road leading to Interbay Dam and Middle Fork Powerplant.   Access the river a short ways below the dam. 
Takeout: Picnic Area just above Oxbow Res (~1160’). River Right just above brigde. Paved roads all the way.
Portages: Two recommended but not mandatory.
·         (Low water only) shallow rapid where the river bends to the left in the first Quarter mile.  Potential portage to avoid shallow boulder jumble
·         ~1/2 mile above Takeout. Double drop of ~10’ into a stout hole w/ undercut on the left + sieve on the right.
·         ~1/2 mile above Takeout. Ledge hole of ~8’, highest drop viewable from takeout road. Note this has a must make eddy on the river left that is challenging. Many would choose to walk the rapid above instead of chance making this eddy. Many folks keep walking from the prior portage on the left.  It is a tough (5-10 min) portage and some oak but most conservative V boaters agree it is worth it to just keep portaging.

A solid crew of class V boaters should budget ~5 hours.   


Other Information Sources:
Middle Fork American River Project Relicensing
Existing Resources Overview pdf
Placer County Water Agency
Upper American River Foundation
UCDavis Hydra Center, flow study news release

StreamTeam Status: Not Verified
Last Updated: 2011-06-14 02:57:44


Rapid Descriptions

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