Hetch Hetchy is a beautiful area. Most people go to Yosemite and neglect to see this beautiful gem. I suggest next time you're heading to Yosemite, stop at HH for the day. The gates are open from 8am-5pm. Free entry during Fall/Winter.
It's closer than driving all the way down to the Valley floor. I plan on making a point to run there more in the future. It's a 3 hour drive and the trails are awesome.
Me doing a little climbing in the tunnel.