[1] The lake, nestled within the southern vestiges of the Sonoma Mountains, is the site of significant Native American prehistoric seasonal settlement.

[2] Tolay Lake and its immediate drainage area is home to several nesting pairs of golden eagles, Aquila chrysaetos,[3] and a number of rare, threatened or endangered species including the California red-legged frog, Rana draytonii; Western pond turtle, Actinemys marmorata; and Western burrowing owl, Athene cunicularia.

Dating to at least 4,000 years, habitation of the original Tolay Lake perimeter occurred on a seasonal basis by the Coast Miwok, Pomo and other native Californians.

[4] Greg Sarris, chairman of the Federated Indians of Graton Rancheria of Coast Miwok or Pomo descent said: "The lake and surrounding area was highly sacred and was considered one of three areas in all of northern California where Indian nomads from different tribes convened for sacred ceremonies and the exchange of ritual objects and songs for the purpose of healing.

Present in the Tolay Lake Basin are a number of well-preserved architectural features, most notably a set of ranch buildings, many of which date from the first half of the twentieth century.

The county is analyzing alternative uses of some of the structures that not only offer preservation, but integration into the educational themes that are to embody the future Tolay Ranch Regional Park.

Considerable biodiversity is found in Tolay Lake and the surrounding hills of the Sonoma Mountains;[10] historical habitats include the lacustrine or marsh environment; grasslands and California oak woodland on higher elevations especially in the steep upland ravine areas.

One of Sonoma County's primary purposes in acquiring the Tolay Lake watershed is the ecological restoration of this area to its pre-European settlement condition.

In that earlier era the lake would have been double its present size and native marshes, grasslands and even some upland forested areas would have been in greater evidence, prior to the destructive force of cattle grazing and other intensive agricultural practices.

Tolay Lake restoration fits into a regional mosaic of open space, conservation easements and wildlife areas in the process of being enhanced.

Ongoing vicinity acquisition efforts further expand the regional landscape of baylands restoration: Petaluma Marsh properties, Dickson Ranch, the New North Point former casino site, and Skaggs Island.

According to a non-profit environmental organization, Friends of Tolay Lake Park: The Tolay land acquisition is magnified by "this integrated effort to regain some of the connections and integrity of the area’s natural systems; together, their restoration will greatly improve the chances of survival for endangered marsh and upland species and will contribute to the overall health of San Francisco Bay".