I see you are riding those hills here in the Sierra Foothills which is my backyard too. I'd say those percentages are accurate. Those old mining roads are steep. My computer that gave the %grade just gave out, but many of our local favorites would give a reading of 16% for a short distance and anything more than that I'm standing up and too far over to see it. Many of our club rides out of Plymouth, Sutter Creek, and Ione have options for these climbs. So, yea - you're climbing - good work!

The profiles are posted for many of the popular(famous?) routes at www.stocktonbikeclub.org. Maybe yours is there?