128 NATURAL RESOURCES SURVEY 



Between McCarty's and Grant's Stations, there is a very 

 recent lava flow which apparently came from the high Mesa 

 country to the southwest. So recent is this flow that there 

 is scarcely any evidence of weathering whatever over its 

 wrinkled, twisted and frothy surface. 



The San Jose occupies a valley far out of proportion to the 

 size of the river, which, coupled with the fact that the pass 

 on the Divide is a very low, wide saddle, about the same 

 width as the valley far to the eastward, seems to substan- 

 tiate the theory that the San Jose once had a much larger 

 drainage area along its headwaters, which, have been divert- 

 ed westward as, in the case of the Puerco, by the subsequent 

 uplift of the Divide, and the present pass is nothing less than 

 an old water gap, now a wind gap, due to the inability of the 

 San Jose to keep downward erosion equal to the upwarp. 

 The largest tributary of the San Jose is Bluewater Cree^k, a 



"Mouth of Bluewater Canon." 



small mountain stream which drains a large portion of the 

 Divide south of the headwaters of the San Jose. This creek 

 at times becomes a raging river of no mean dimensions or 

 importance when heavy rainfall occurs along the roof -like 

 eastern slopes of the Divide. Bluewater Creek flows through 

 a box canyon before it reaches the lower valley. For a dozen 

 miles or more this canyon arises in perpendicular walls, at 



