<P> The Ohlone tribe settled the area in 2000 BCE, particularly in the northern part of Pleasanton . In 1772 CE, however, Spanish settlers involved with the nearby mission work at Mission San Jose strongly influenced the Ohlone way of life . </P> <P> The area began to be developed when the Gold Rush ended . During this period, the area went from being marshland to agricultural . </P> <P> The Tri-Valley is serviced by WHEELS, operated by LAVTA, formerly called Tri-Valley Transit, a bus agency that operates local bus service in addition to feeder service to Hacienda Business Park, Lawrence Livermore National Laboratory, Las Positas College, Stoneridge Mall, and Dublin / Pleasanton BART station . </P> <P> Two major highways, Interstates 580 and 680 cross the Tri-Valley area . Interstate 580 runs east - west, connecting the area to the Central Valley to the east and the North Bay area to the west . Interstate 680 runs north - south, connecting the area to the South Bay area in the south, and the Concord - Walnut Creek area in the north . The two interstates cross on the border of Dublin and Pleasanton . </P>

What are the tri cities in northern california