A Franciscan retreat center in Danville (Bay Area, Google drive time 1 hour 7 minutes).
A Sisters of Mercy retreat center in Auburn (north of Sacramento, Google drive time 1 hour 23 minutes).
A Sisters of Mercy retreat center in Burlingame (Bay Area, Google drive time 1 hour 31 minutes).
A Jesuit retreat center in Los Altos (Bay Area, Google drive time 1 hour 36 minutes).
A Franciscan retreat center in San Juan Baptista (in the coastal range between Monterey Bay and I-5, Google drive time 1 hour 58 minutes).
A Trappist monastery in Vina (in the vicinity of Chico, Google drive time 2 hours 41 minutes). To access their retreat information, mouse over Mary, then click local community, then welcome center; then click retreat information.
Peruse the retreat centers, and take a look at their list of upcoming retreats--or make an individual retreat with help from one of their retreat directors. Go it alone--or take a friend, or several. Money will not get in the way, since some (like Abbey of New Clairvaux) will take whatever is affordable for you. They will even pick you up at the bus stop!
Watch for Newman House retreats as well!