PHYSIOGRAPHIC SIGNIFICANCE OF THE MESA DE MAYA. 
BY CHARLES R. KEYES. 
The Mesa de Maya is • a small elevated tableland lying on the 
borders of Colorado and New Mexico, between Trinidad and Raton. 
It has an elevation of over 9,000 feet above sea-level and about 
3,600 feet above the valleys on either side. 
This mesa is a part of the Raton range of mountains which 
trends slightly south of east along the southern boundary of Col- 
orado. It is lava-capped, as are also many other similar flat- 
topped mountains in the same range. The lava-cap is 500 feet in 
thickness. On the borders of the mesa is a vertical cliff all 
around — hence its name, the Spanish meaning “armored mesa.” 
The Raton range, of which the Mesa de Maya is a part, extends 
eastward, at right angles, from the Rocky cordillera. The sum- 
mits of the individual mountains and spurs which go to make up 
the range are quite even; and many like the Mesa de Maya are 
covered by remnants of old basalt flows. The general even surface 
which the range everywhere exhibits, is manifestly merely a frag- 
ment of a much more extensive surface that once existed. It 
is all that remains of an old plain of great extent. This old 
plain bevels the tilted stratified rocks of its substructure. The 
old plain is inclined slightly towards the eastward. At the Rocky 
Mountain front it has an elevation of about 10,000 feet above 
mean-tide; at the Texas line 130 miles away, it is about 5,000 
feet above sea-level. The geological and physiographical relation- 
ships are shown in the accompanying diagram: 
The even level, which the top of the Raton range represents, is a 
physiographic feature that has been given the designation of the 
Mesa de Maya plain. It is now a mere ragged remnant of a plain 
(221) 
