That route includes a fair amount of dirt-- fire roads and single track. Were you looking for a road route or was this what you had in mind? I think this would be tough on a road bike unless you have a lot of experience on dirt. But perhaps you are renting a mountain bike....

If you are looking for a road route, check out the velogirls.com route sheets, there are many routes there going out from near the golden gate bridge into marin. Some routes I like:
Paradise Loop-- about 38 miles from Presidio Sports Basement. Rolling, no significant climbs, really really pretty ride

Alpine Dam-- a really fantastic ride up Mt Tam, about 50 miles from PSB. Great views if it is clear. Has sustained climbs (VG route sheet says around 4000 feet of climbing for the trip, I think it's a bit less but still several sustained climbs then a nasty set of "rollers" called the seven sisters)

Cheese Factory/Nicasio/Pt Reyes Station-- there are a series of marin farmland routes, several of which go out to the coast. These tend to lack sustained climbs, but there is definitelly rolling california terrain.

Also fun, but possibly not what you had in mind is the 49 mile scenic drive around the streets of san francisco (but try and take the SF bike coalition alternative route, which bypasses some of the more gnarly less scenic bits). You go down twisty lombard street, out the marina, through presidio, to ocean beach, up twin peaks-- basically loop the city on roads considered to be the prettiest or most interesting.
Good luck