The 25th annual McKenzie River Trail Run

Originally a 50 mile race, it converted to a 50k event after 10 years. Noting the anniversary this year, the 50 miler was brought back in honor of the oldest continuously held ultra run in Oregon.

Here's a review from 2010

http://blog.oregonlive.com/runoregon/2010/09/mckenzie_50k.html