San Justo Reservoir is a popular fishing spot in California, known for its abundance of largemouth bass, bluegill, and crappie. Visitors can engage in various recreational activities like hiking and picnicking, and the park also offers boat rentals. Anglers can find the best fishing spots in the deeper areas of the lake, where the fish are more active. The best time to visit is during spring and summer, with average temperatures ranging from 70-85°F. Fishing tips include using live bait and fishing during early morning or late afternoon hours.