NO. 3 



SMITHSONIAN EXPLORATIONS, I915 



25 



Fic. 36. — \'ie\v near the moutli of Squaw Creek, West Gallatin River Canyon. 

 The rocks in the immediate foreground on the right are of pre-Cambrian age, 

 those in the cliffs at the base of Castle Mountain are of Cambrian age, the 

 cliffs just below the summit of Devonian age, and those forming the castle on 

 the summit, of Carboniferous age, the entire section embracing over 3,000 feet 

 of bedded limestone. Photograph by Walcott. 



^^ 



Fig. 37. — Rural delivery station. Deep Creek Canyon, Belt Mountains, 16 

 miles east of Townsend, Montana, where we received a promptly delivered 

 daily mail. Photograph by Walcott. 



