Interior Valley: Tolay Lake


Tolay Lake Regional Park is unique; most other valleys this close to highway 101 and San Francisco are covered with asphalt and shopping centers. Sprawling estates creep up the hillsides as if to say on behalf of their owners, “I just love this place! Let’s tear out all those messy trees, put in tennis courts and plant oleander.” But Tolay has been spared that fate. Uphill from the Petaluma River and west of the rolling hills south of Sonoma Mountain, it is thought to have been a sacred site for Native Americans as evidenced by the nearly 1000 arrowheads and charmstones found in and around the lakebed. European immigrants modified the land to make it more arable, and today Tolay is a seasonal lake, at least it is in winters when the rainfall is sufficient. In recent years there has been no lake at all, but December’s rains were enough to collect a good amount of water in the basin.

Tolay is a popular destination for birders: as the largest freshwater lake in the area, it supports a diverse population of raptors and other birds. One time I was there in the early evening with a friend and she kept reporting “tiny hawks disappearing into the ground.” I realized she was seeing Athene cunicularis, burrowing owls, which are considered a species of concern due to habitat loss. It’s also home to the threatened red-legged frog.


But the park is sadly lacking in healthy plant populations.The regional park brochure uses the word “pristine” to describe the grasslands (among other features) in the park, but I noticed the same plants that are evident in other unstrategically grazed pastures and disturbed areas like vineyards: there is a lot of mustard,  and many non-native annual grasses.  I did find two populations of the beautiful and poisonous star or zigadene lily, Toxicoscordion fremontii.  A master plan for the park includes habitat restoration as a goal.

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The most dramatic attractions in Tolay Regional Park are the views. For a moderate climb you get enormous views of Mount Tamalpais,the Petaluma River Valley, Mount St. Helena, the entire western flank of Sonoma Mountain, most of San Pablo Bay and three of its bridges, and on a clear day the San Francisco skyline and part of that bay.

Tolay Lake Park is only open on weekends, and visitors must attend a brief orientation to obtain a pass. But it’s absolutely worth it. It’s an exceptional place to visit for so many reasons.


© Hannah Aclufi and, 2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited.

One thought on “Interior Valley: Tolay Lake

  1. I love this marshy estuary type landscape. I have heard of an interesting buildings in the park. Love to go with you sometime. I will drive up to the gate just for the view on nice days.


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