2020 Map of Peterson Ridge

About this map

Peterson Ridge and Blalock Mtn anchor this high-elevation corner of Umatilla County, where the landscape is defined by the deep drainage systems of the N Fork Walla Walla River and the numerous branches of Cottonwood Cr. The map reveals a network of early access routes including the Morman Grade and Saddle Mountain Rd that navigate the ridges between Pikes Peak and Saddle Mtn. This area's geography is characterized by distinct landforms like Pumpkin Hollow and Cup Gulch, illustrating the complex erosion patterns north of the Walla Walla River. The distribution of roads such as Government Mountain Rd suggests a landscape managed for timber or grazing, with small clearings like Little Meadows providing breaks in the high-country terrain of Pine Ridge.