William R. Mason Regional is a nice large park, featuring 2 joining lakes. A brick bridge spans the meeting point of both lakes. There are accomodating bike/walking trails which circle the lakes, as well as the park. There's a $3 Vehicle Entrance Fee Monday's thru Friday's, $5 Car Entrance Fee Saturday's, Sunday's & Holidays. Lovely mature trees grow everywhere here amidst a spacious meandering lawn. This green natural carpet provides a perfect place to spread out and have a picnic, or play games on. On the west end of this park, there's a low-fenced retreat area, featuring many bright, colorful flowering plants. All these flowers attract lots of butterflies & hummingbirds.

There's a creek which runs along the front of the park, on University Drive, with eucalyptus trees planted here. They provide shade and a nice habitat for birds. I saw a Great Blue Heron fishing in the creek here, as well as various small bird species up in the trees.

I spotted 2 Red-Eared Turtles crawl out of the lake, and up onto a large rock. They were enjoying the warm sunshine.

I also saw several Western Bluebirds up in the park's large deciduous trees, plus hummingbirds and White-Crowned Sparrows in the semi-private retreat area on the west end of the park.

Across Culver Drive, a bike trail continues along a green open space area, with lots of trees, greenery, and a grassy hillside on the southern side of the trail. A small creek is visible about the midway point of this bike trail, where you could see Snowy Egrets or ducks. When you enter this bike trail, across Culver and adjacent to the park, there's a sign warning people of the possibility of seeing mountain lions, rattlesnakes...etc. This freaked me out the first time I biked here, but I've never encountered any dangerous critters on this bike trail. I have seen several Red-Tailed Hawks soaring above this beautiful green nature area, plus lots of ground squirrels & lizards, too.