MAXWELL COULEE AND THE DIVEKSION OF THE EIO MOEA. 
BY CHARLES R. KEYES. 
{Abstract.) 
jMaxwell Cone or Bald Mountain is a low eminence rising out of the 
plain at the south foot, of the Turkey mountains, in northeastern New 
Mexico. The last mentioned mountains form a rather conspicuous circu- 
lar ridge of high hills having an even crest. These mountains are situ- 
ated ‘about 30 miles northeast of Las Vegas and about 20 miles east of the 
Eocky mountain front. The vast even plains stretching out to the east- 
ward of the Eockies in this region is a part of the Las Vegas plateau. 
klaxwell mound is a typical ash-cone. It rises scarcely 400 feet above 
the general level of the plains. As viewed from the railway train six 
miles away,- and against the high . Turkey range, it is quite inconspicu- 
ous. The crater is perhaps 1,000 feet across, and on the southern side 
is breached. Through this breach extends a notable flow of basalt. Near 
the volcano the flow is five to six, miles broad; and for a distance of 8 
miles it retains this width, when it abruptly becomes narrower as it 
enters the canyon of the Eio Mora. It continues down the Mora canyon 
to its junction with that of the Eio Cimarron, a distance of 30 miles. 
The lower end of the basalt flow was early noted by Stevenson.^ The 
crater was incidentally visited by LeConte, Newberry and Hayden. The 
lava-stream has been passed over on the cars by many geologists on their 
way to the Southwest. Between Tipton and Shoemaker stations, a half 
hour’s ride from Las Vegas, the Atchison, Topeka and Santa Fe rail- 
road traverses the great flow for a distance of several miles. From the 
train a fine view of the breached crater is obtained to the northwest ; and 
to the southeast the flow may be easily followed with the eye until it dis- 
appears into the Eio Mora canyon. 
Two especially instructive features present themselves in this connec- 
tion. One point is the diversion of the Eio Mora itself by the lava-flow; 
and the other is the amount of stroam-corrasion which has been accom- 
plished since the basalt first occupied the canyon. 
*American Jour. Sci., (3), Vol. XXI, p. 154, 1881. 
