2015 Map of Slack Canyon

About this map

The San Andreas Fault cuts a distinct NW-SE diagonal through this portion of the Diablo Range, creating a complex landscape of valleys and ridges along the boundary of Fresno and Monterey Counties. This tectonic feature largely dictates the local drainage and topography, with Peachtree Valley and Pancho Rico Valley running parallel to the fault line. The area is characterized by numerous seasonal water sources and named springs such as McMillan Spring, Little Bitterwater Spring, and Brock Springs, which were critical for ranching in this arid environment. Roads like Peach Tree Rd and Indian Valley Rd follow the natural contours of the primary valleys, connecting remote canyon networks including Slack Canyon and Little Bitterwater Canyon. The map reveals a sparsely populated terrain where the geometry of the Public Land Survey System overlays a geology-driven landscape of deep canyons and high ridges.