EXTENT OF THE DENVER. 195 



tributaries of Coal Creek, still farther east, are rich in outcrops, the more 

 noteworthy of which will be specified. 



Sand Creek is the name applied to the lower pari of the important 

 tributary of the Platte entering it just below Denver. About 2 miles 

 above the Kansas and Pacific Railroad crossing the stream forks, the eastern 

 branch being known as Coal Creek, while the more southerly one is called 

 Toil-Gate Creek or simply ( rate Creek. Coal Creek heads nearly 30 miles 

 south-southeast from this junction, in the Monument Creek plateau region. 

 Gate Creek has many branches which drain nearly all the interior of the 

 region between Coal and Cherry creeks, and its headwaters arc (in the line 

 where the Denver beds pass under the Monument Creek strata. 



Passing up Coal Creek from the forks there are some fine-grained, 

 shaly outcrops on the southern banks, in the angle between the Kansas 

 and Pacific Railroad and the High-Line ditch, hut they are not specially 

 characteristic. Beyond the ditch crossing the first outcrop is almost 

 exactly on the line of the eastern boundary of the map, where a little 

 gully coming from the west has cut into and exposed a sandstone resting 

 on clay. The sandstone is friable, with large, hard nodules characteristic 

 of the formation in this region. The eruptive character of much of the 

 material is clear. Apparently this part of Coal ('reek is very near the 

 line between the Denver and Laramie, the Arapahoe being absent. 



One mile above the last-mentioned outcrop Murphy Creek joins Coal 

 Creek from the south, only a narrow ridge separating them for 2 miles 

 upward. This lower portion of the ridge is composed of Laramie, capped 

 by a thin sheet of Monument Creek sandstone, a relation well shown mi 

 the Coal Creek side. No further exposures of the Denver beds occur on 

 Coal Creek until a point 5 miles above the mouth of Murphy Creek is 

 reached, an occurrence to be mentioned below. 



Murphy Creek now becomes the parting- line between Denver and 

 Laramie strata, and 1 mile above its mouth there is an outcrop of Denver 

 sandstones, with dark nodules on the western bank, while on the eastern 

 the slope is underlain by the Laramie. Above this outcrop the Laramie 

 seems to cross the western bank and extends up to where the old Smoky 



