6 
PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 64, Supplement 1 
Table 1. Major types of sites in the regions, of which 997 caves were sampled, 22% of the known 4,600 
caves. The total number of California mines exceeds 39,000. See Methods for a description of the Kryptos 
database. 
Figure 2. An outcrop of McCloud Limestone above Shasta Lake that contains Samwel Cave. Tree roots penetrate the 
cave via two entrances and cracks. Jessica Blois. 
northern Trinity, and western Shasta counties in the Klamath, Shasta, and Trinity National Forests 
(Fig. 1). Mostly the caves are in carbonate rocks — limestone and marble. Table 1 lists 197 caves 
biologically sampled. In addition to scattered sites throughout the region, four distinct areas with¬ 
in the Klamath Mountains region contain subterranean sites. The Marble Mountains Karst 
contains a group of caves in Klamath National Forest. Elevations generally range from 
