Black Mountain via Rhus Ridge is a 9.8 mile out and back trail located near Los Altos, CA that features beautiful wild flowers. The trail is rated as difficult and primarily used for hiking, walking, and trail running.
Towering over Silicon Valley, waaaay back to the rear of Rancho San Antonio, lies 2812' Black Mountain. Starting at the little-known Rhus Ridge parking lot, you can enjoy a healthy workout and a grand panoramic view of Silicon Valley.
This is a long, fun hike, though would not recommend it on warmer days. It was a pretty steep start and lasted for about a mile, till we hit the black mountain trail. The black mountain trail is mostly flat with a few ups and downs and is around 3.9 miles. The last section is pretty steep and mostly exposed. Lots of fence lizards on the trail and in parts some dried wildflowers. All in all a strenuous but fun hike!