Frog Pond

Since the frog pond was constructed in 2018, Parks has been monitoring its use. Red-legged frogs continue to be observed nearby. Wildlife cameras have detected bats, bobcats, deer, ground squirrels, jackrabbits, opossums, raccoons, quail, and skunks. Egrets, northern flickers, western kingbirds, and many other birds also make use of the pond. Vegetation is doing well, with willows and cattails filling in. Because it can take several years for the pond bottom to harden, bentonite clay may be added to the bottom, to optimize water retention.

The California red-legged frog was designated as the California state amphibian in 2015. Once common, the frog has disappeared from about 70% of its range, due to habitat loss and the introduction of competing predatory species. Growing up to five inches long, it is the largest native frog in the western United States. In the past, thousands of red-legged frogs were harvested annually for their legs, which were considered a culinary delicacy. 

The red-legged frog is currently listed as threatened under the U.S. Endangered Species Act and a species of special concern under California law. After the discovery of an adult red-legged frog in a small spring on Mount Burdell, the frog pond project was designed to create new aquatic habitat during this time of uncertainty in our environment. This project intends to provide a home to a variety of amphibians and support other wildlife.

• Provide protected aquatic habitat for the California red-legged frog and other amphibians.
• Blend in with the natural beauty of surrounding grasslands.

• .26 acre pond with a maximum depth of 5.5 feet that can hold .2 acre-feet of water.
• Spillway to discharge overflow into a seasonal stream; drainpipe to help control invasive species.
• Cattle access to allow seasonal grazing that will manage encroachment of vegetation and allow frogs to enter the pond.

• December 2015–Spring 2018: Project planning, site assessment, design, permits
• July 2018–October 2018: Construction and bio-monitoring
• January 2019: Begin planting wetland vegetation
• Fall 2020: Line pond with betonite for water retention

The Marin County Open Space District (MCOSD) prepared an evaluation which determined that pursuant to California Environmental Quality Act (CEQA) Section 15333, this small habitat restoration project would not result in any potentially significant environmental impacts. The MCOSD filed a Categorical Exemption on March 8, 2017, in compliance with CEQA.

• Categorical Exemption pdf