Castaic Lake has two bodies of water. Lower lake is for non-power boating and canoeing. Swimming season on lower lake runs from mid-May to mid-September. Upper lake is for sailing, power boating, water and jet skiing, and fishing. The lake is stocked with bass, trout and catfish. Boat rentals and a tackle bait shop are available.
Other recreational activities include hiking, biking trails, picnic areas and playgrounds. Rental group picnic areas are available for up to 600 persons.