At almost 4000 feet, Mt Diablo towers over the skyline of the San Francisco Bay area. Although it isn't the highest mountain in the Central Coast Range (Mt. Hamilton is a bit higher), it is by far the most noticable. It has two main peaks, a northern one and a southern one. The whole area is a state park, and a very twisty road leads to the southern peak. From the top you can see a large chunk of the high Sierra, most of the Central Coast Ranges stretching to the south, the sprawling bay area cities (if it isn't foggy), and the other major mountains of the area (Mt Hamilton, Mt Tamalpais, Mt St Helena, and if it's very clear, the Sutter Buttes, Mt Lassen, and possibly Shasta or Half Dome). Between the Sierras and the coast ranges lies the Central Valley, a huge agricultural center, and to the northeast the Sacramento River Delta and the Carniquez Straight through which the whole valley and most of the Sierras drain.

Mt. Diablo is carpeted with live oak and chamise. This gives it a very black color from far away; perhaps this is why the mountain was named after the Devil. Since the mountain is so much higher than everything else nearby, it gets the full force of storms. Usually the mountain just gets a cold, driving rain, but during particularly cold storms it may get a few inches of snow. During summer mornings, the fog swirls around the peak as it pours over the hills, making its distinctive rugged peak into an apparent island. In the spring, the normally black-brown sides of the mountain are a verdant green. In the fall, strong winds buffet the peak, and on many winter days the summit is shrouded in rain clouds.

Mt Diablo is one of the main landmarks of Central California as it can be seen from just about anywhere in the area. It seems odd that it was named after Satan, as it has always been a comforting sight to me.