172 GEOGRAPHIC DISTKIBUTION. 



and firs are growing, and hundreds, thousands of little basins filled with 

 clear, cold water are found. These glacial deposits are doubtless of much 

 later origin than the Bishop Mountains-Conglomerate; often they are min- 

 gled with and masked by drift which has been brought down from the 

 heights by storms, and in many places it is impossible to separate that which 

 is due to this latter agency from that which is due to the agency of ice; and 

 as you descend the valleys away from the peaks where the glacial snow was 

 accumulated the mingling of the two increases by an increase in the amount 

 of drift until at last the glacial formation is lost and drift only appears ; taken 

 throughout the Uinta Mountains, the glacial material is far less in quantity 

 than the drift material. What I have thus described as glacial action is 

 exceptional or local and trivial as compared with drift agencies, which must 

 always obtain in mountain regions alike when they are free from glaciers or 

 when the elevated valleys are filled with ice. 



Thus the glacial epoch in the Uinta Mountains was doubtless a reality; 

 the evidences of such a time are abundant, but they are found only high up 

 on the range, and the gravels and bowlders of the lowlands attest only to 

 the ordinary action of drift agencies. I may remark here that the evidences 

 of the same glacial epoch are abundant in the Park Mountains; but there 

 also the glaciers were confined to the elevated ranges. The gravel beds on 

 the lowlands are true drift. 



LIGNITIC COAL. 



But little reference has been made to the lignitic coals found in the 

 Uinta region; it is expected that the coals of the Plateau Province will be 

 discussed in a separate volume. 



