Causeway Trail to Three Bridges Vista Point Professional Guide
Detailed Trail Description from our Guidebook
"Tolay Lake is a freshwater lake that sits in a bowl-shaped basin bordered by low rolling hills between the Petaluma River and Sonoma Valley. The seasonal lake is fed by Cardoza Creek and 18 other springs. The lake bed fills during the wet winter months, but it is mostly a large freshwater marsh or a dry lake bed during the dry season. The lake originally covered 400 acres, but it is now a fraction of that size. In the 1850s, the natural dam that helped to create the lake was demolished, and the lake was drained for agricultural purposes. The Tolay Basin is a significant site of ancient Native American settlements that date back nearly 10,000 years. The sacred site is associated with the belief in the lake’s healing powers. It was a regional gathering place for tribes, including the Coast Miwok and Pomo, for the purpose of ceremonial healing. Tolay Lake Regional Park was established adjacent to the lake. In addition to the lake, the 1,769-acre park contains wetlands, marshes, ponds, ephemeral creeks, grasslands, meadows, open rolling ridges, mature oak groves, and scattered eucalyptus trees. This hike leads to the Three Bridges Vista Point atop a 750-foot ridge, where there are sweeping views of the Richmond–San Rafael Bridge, the Bay Bridge, and the Highway 37 overpass. The views also include downtown Petaluma, Mount Diablo, Mount Tamalpais, Mount Saint Helena, the Sonoma Range, San Pablo Bay, and the Petaluma River Basin. The route to the overlook follows the Causeway Trail along an earthen embankment that bisects Tolay Lake, then climbs up the ridge through an oak woodland."