The Del Valle Regional Park, Livermore, CA., is located on Del Valle Road off Mines Road.  From I-580 take the North Livermore Ave exit and head south 3.9 mi (North Livermore Ave will become South Livermore Ave).  Turn right onto Mines Road. Go 3.5 miles and continue straight on Del Valle Road (Mines Road turns left). Drive 4 miles over the hill to the park entrance (there is a parking fee).  After the entrance go right and park near the lake.  https://www.ebparks.org/parks/del_valle/