Mount Vaca is a mountain in Napa and Solano counties of Northern California.

Although cattle ranching historically played an important role in the area, Mount Vaca and the nearby city of Vacaville are actually named for Juan Manuel Cabeza Vaca (1782–1856), who with Juan Felipe Pena received in 1843 the Rancho Los Putos Mexican land grant, which included the peak that now bears Vaca's name.

As a consequence, television station KPIX-TV, a San Francisco CBS affiliate, partnered with the National Oceanic and Atmospheric Administration (NOAA) to build a Doppler weather radar on top of Mt.

Before this, the mountain blocked radar information about storms coming in from the Northwest, which compromised weather prediction and allowed for flooding, heavy rains, and high winds without prior warnings.

This new radar system gives meteorologists a more complete view of precipitation and temperature patterns in the Bay Area, and allows for more accurate weather predictions.