How is it that Vacaville ended up with arguably the two toughest medium length climbs in California? And how is it that they are only 2 miles apart? I don't know, but I do know these are two of the hardest climbs I've ever done.
Mix Canyon climbs 2178 feet in 4 miles, averaging 10.3%. The 10.3% is misleading, however, as the first 1-2 miles are rather sane. The steepest mile averages an incredible 15.8% (for a reference point, Old Priest Grade only averages 15.0% for its steepest mile and Bohlman/On Orbit averages a puny 14.6%). In Summerson's California climbing book, Mix Canyon is #1 on the list for steepest mile sections and #3 for steepest half mile (16.2%).
Gates Canyon is not listed in the climbing book but is similarly hard. Total climbing for the day was about 4500 feet. My legs were done by the end of it.
The full ride report with all the pictures and maps is here:
Vacaville – The Diabolical Duo – Mix Canyon & Gates Canyon (Super Steep) Hill Climbing
And some pictures to entice all of you who like the steep stuff..
Mix Canyon:


Gates Canyon:

Fun stuff