Been there twice. It's a good day from San Felipe, not long, but save lots of daylight for the 20 MILES of good offroad driveway up to Mike's. Can be quite challenging with a full load. Expect to either work the suspension really hard on some climbs (not fun with a loaded f650GS) or drag the clutch a bit. Save some jam for oft-deep but really easy water crossing right at the end. If you're not loaded and you're motoring it takes about an 45 minutes from the turnoff. Loaded, 3 bikes, thrown chain, sundown, add about 3 more on top of that...but that's another story.
PS I realize this thread is ancient, but it could come up in a search!