I hiked up Mt. Olympia on 1 June, climbed Mt. Diablo via the Mt. Diablo 25K race the next day, then hiked up Eagle Peak the day after that. The park was hot and dry, with lots of coyote poop on the trails.
Did the 4 Summits Hike, taking on Eagle Peak, Diablo, North Peak and then Olympia, so I took the Olympia Trail down. Unfortunately, what started out as a nice day turned out differently, as the clouds came in and completely covered the top 2500 feet of the mountain. No views, but still a hike to remember.
Didn't use the whole Olympia Trail; instead used Four Summit Loop from Mitchell Canyon. Traversed to Mt. Olympia directly from North Peak (that was a little nutty, but not as bad as the SP description made out).