1. Geologic map of the Weaverville 15ʹ quadrangle, Trinity County, California Author/Creator: Irwin, W. P. 1919-2012 (William Porter) Publication/Creation: Washington, D.C. : U.S. Dept. of the Interior, U.S. Geological Survey, 2009 Resource Type: Map Access & Availability: Loading
2. Geologic map of the Klamath Mountains, California and Oregon Author/Creator: Irwin, W. P. 1919-2012 (William Porter) Publication/Creation: Denver, CO : For sale by U.S. Geological Survey, Map Distribution Resource Type: Map Access & Availability: Loading