The park was named after William R. Mason, a prominent Irvine Company executive who helped shape the early development of Irvine.
The park is situated on land formerly used for large-scale lima bean farming before the rapid urbanization of Orange County.
The lake features a man-made concrete liner and acts as a central hub for the park's migratory bird population.
It is one of the few regional parks in Orange County that integrates directly into the UCI campus trail network.
The park utilizes a reclaimed water system for its extensive irrigation needs to minimize environmental impact.
William R. Mason Regional Park is a 339-acre oasis in Irvine, featuring a three-acre lake and extensive multi-use trails. The park serves as a green buffer between residential Irvine and the University of California, Irvine campus. Recreational facilities include three softball fields, a nine-hole putting green, and several volleyball courts. Hikers can access varied terrain ranging from manicured lawns to native California coastal sage scrub habitats. The park landscape was designed to incorporate both mature sycamore and oak trees, providing significant natural canopy. It serves as a popular venue for large group events due to its numerous reservable picnic shelters. Birdwatchers frequent the central lake area, which attracts various waterfowl species year-round. The park grounds provide direct access to miles of interconnected regional bicycle trails.
The pedestrian bridge overlooking the central lake during golden hour.
Bring polarized sunglasses to better view the wildlife in the lake.
Secure a reserved picnic shelter in advance if you plan to visit on a weekend for a large gathering.
Use the trail networks to connect to the adjacent San Joaquin Wildlife Sanctuary for extended hiking.
Feeding the ducks and geese, as it disrupts their natural diet and causes water quality issues.
Park grounds are generally accessible year-round, though specific amenities like sports fields may occasionally close for maintenance or tournament reservations.
Dogs must remain on a leash at all times; alcohol consumption is restricted to designated areas with permits.
