Just east of Morgan Creek, Mount Sizer may not match Diablo, Tamalpais and Saint Helena for eye-popping scenery, but it gave the masochist in me all I could ask for (and the views of the green hills were nothing to sneeze at either). If you want the kind of hike where you really feel like you've been on an adventure afterwards, Sizer will scratch that itch and then some. Another way of putting it would be to say that it's punishing. Our journey up to the peak (a modest, unassuming peak if I'm being honest) involved crossing a creek with thigh-high waters and then immediately scrambling up the steepest trail in the Bay Area. I had heard it was the steepest in the Bay going in, but I didn't exactly grasp how steep that would be. The answer is incredibly steep. You won't feel like you're in danger going up it but you will feel like you're going straight up and up and up for a while before you reach the top. And again, we were made to do this mere seconds after wading up to our boxers in a chilly creek. Another thing the Mount Sizer does is climb a lot. Obviously for any hike you need to go up as much as you go down. But we couldn't shake the feeling on this one that we were going up an awful lot. Remember the old person adage about walking to school uphill both ways? Mount Sizer is the “uphill both ways of hikes”. It's not a matter of simply getting up it and going down it. On the way down, we had to go up a few more smaller mountains. On most hikes, you think the way back will be a little easier, but I found Sizer equally challenging in different ways going to the summit and coming back. It's not the first one I'd go back to but I felt electrifyingly exhausted at the end of it. It has as much sheer challenge as you could ask for. Trails that feel nearly vertical. Swift waters to cross. A never-ending rollercoaster of ups and downs. We even had to make our way through a pack of male turkeys who were out enjoying their own hike. Sizer is not always friendly but it is beyond rewarding. A real four-course meal for the hungry explorer!