The Tri-Valley is an area in the East Bay in northern California.
There are five main cities and towns in the Tri-Valley. In the south are the cities of Pleasanton and Livermore, and in the north are the cities of Dublin and San Ramon and the town of Danville.
The Tri-Valley is in the East Bay region of California, consisting of these valleys:
Although Tri-Valley is quite densely populated, the mountainous terrain around it is almost uninhabited.
In the 1800s, European settlement of the region began with some unimportant buildings in the Dublin area. In 1850, Pleasanton became the first incorporated city in the region. Then, in 1869, Livermore became the second. In 1982-83, Dublin, San Ramon, and Danville also became incorporated.
The movie industry came to the area in the early 1900s (in particular Pleasanton), but it moved completely to Southern California once talkies began to dominate.
The area, due to its Mediterranean climate, is good wine country. Vineyards are abundant in the south side of the Tri-Valley.
I-580, I-680, and CA-84 highways go to the region. These roads, however, can be become very busy at almost any time of year.
The Altamont Commuter Express has a train station in Pleasanton.
There are major roads around the area, making travel relatively easy. There are two freeways (interstate highways), the I-580 and the I-680, along with a California State Route, the CA-84.
Del Valle Regional Park, an East Bay Regional Park, is one of the region's main attractions. The park goes around Lake Del Valle, a reservoir that was built about fifty years ago. There are numerous trails that go through the hills and mountains around the lake, including one that goes almost directly below some Bryce-like cliffs. Del Valle Park is also a useful gateway for reaching other local parks and wilderness areas, including the Ohlone Regional Wilderness, which goes for more than 20 miles (32 km) into some of the remotest parts of the Diablo Range and even California in general. Other East Bay Regional Parks in the Tri-Valley and surrounding areas include Morgan Territory Regional Park, Sunol Regional Wilderness, Las Trampas Regional Wilderness, Brushy Peak Regional Preserve, and Dublin Hills Regional Park.