46 



GEOLOGIC GUIDEBOOK ALONG HIGHWAY 49 



[Bull. 141 



Fio. 15. "Natural Bridge," a limestone cave, situated between Columbia and Vallecito, 

 through which Coyote Creek runs. Photo by Olaf 1'. Jenkins. 



Kiii. 14. Marble quarry north of Columbia. Tuolumne County, located on a side road 

 to the east of the Colombia-Parrot Kerry road. Photo by Olaf P. Jenkint. 



Kio. 16. Mine buildings of the United States Lime Products Company lime plant at 

 El Dorado. Photo by Olaf P. Jenkins. 



