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MATO Tin. 283 



SECTION VII. 

 THE BEAE LODGE COUNTRY. 



Forming- the extreme nortlnvestern part of the Bhick Hills, and sej)- 

 arated from the main rajige by the broad oi)en valley of the Kedwater, tlie 

 Bear Lodge country has a geological system and topography which, while 

 a miniature counterpart of that characterizing the main range of the Jilack 

 Hills, is a distinct uplift, produced by the intrusion of the igneous rocks 

 forming Warren Peaks. Covering an area of nearly one thousand square 

 miles, mostly included between the Redwater and the Jjclle Fourche, this 

 region takes its name from a singularly-shaped trachyte butte, '^Mato Tip'),'' 

 or " The Bear's Lodge." Surmounting a hill near the north bank of the 

 latter stream, this butte forms the most cons})icuous landmark in the region, 

 resembling the base of a ruined and crumbling column, with its shaft nearly 

 500 feet in height, and the top 1,127 feet above the water in the Belle 

 Fourche. 



Warren Peaks, a cluster of high rolling hills, grass-covered, and 

 nearly destitute of timber, are the most elevated points in the Bear Lodge 

 range, almost equaling Harney Peak in height, their tops being from 

 G,700 to G,800 feet above the level of the sea. 



Occupying an area about four miles in diameter, these peaks are com- 

 posed of coarsely- crystallized feldspar-trachyte, apparently destitute of 

 quartz, but sometimes containing hornblende and mica, and often having in 

 the arrangement of the crystals of feldspaj", in a granular matrix, a struc- 

 ture-like porphyr}'. This rock, which is seen of different shades of gray, 

 yellow, and reddish-brown, seems to be quite readily decomposed by 

 atmospheric agencies, and, crumbling away, has given rounded surfaces 

 and outlines to the hills and ridges. Standing on any of the higher of 

 Warren Peaks, the view shows at once the distant character of the uplift 

 and the peculiarities produced by it in the topography of the region. 



The central peaks are surrounded l)y others of less elevation, between 

 wliich ravines radiate in every direction like the spokes of a wheel from 



