I rode 38 miles today with roughly 1,400 feet elevation gain. You rode a tough one. All my elevation gain was in the 3 miles going over chino hills to diamond bar. I almost died on grand avenue; thought i was going to have a heart attack soon enough. I was going up at snail pace.
Mapmyride.com is a website I use to figure out the distance, sometimes plan my routes ahead of time (remembering the name of the streets I take turns on) and a nifty bonus to that site is that it gives you elevation gain and also the percentage of the incline.
The toughest climb I did so far is the carban canyon road switchback from chino hills to brea. I wanted to know the percentage of that climb and according to the site its over 15%!!! But the climb is 3 quarters of a mile long so most climbers wouldnt have any problems with it. Im not really a climber so I struggle up that hill every single time. It hurts. Did that route more than two dozen times and it still hurts. Im pretty sure most socal riders have done the carbon canyon road though so I could be just writing a whole lot for nothing.