2015 Map of Detert Reservoir

About this map

The Palisades stand as a dominant geological feature in this portion of the Mayacmas Mountains, where the borders of Lake, Napa, and Sonoma counties meet. The landscape is defined by dramatic elevation changes, from the heights of McGuire Peak and Three Peaks down to the drainage of Saint Helena Cr and the Collayomi Valley. This map documents a region heavily influenced by its volcanic geology and hydrology, centered on the Detert Reservoir and the adjacent Lake Bordeaux and Lake Burgundy. The presence of the Oat Hill Mine Trail and Western Mine Rd reflects the area's industrial past, while the modern footprint is seen in thoroughfares like Guenoc Winery Rd. Notable landmarks such as Hole in the Rock, Table Rock, and Sugarloaf Mtn punctuate the ridges above Jericho Canyon and Bear Valley.