276 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Marvin, Mr. Henry Gannett, and Mr. G. R. Bechler, carried 

 on distinct and independent work. 



Professor Hayden's party made a special study of the Elk 

 Mountains, a very high and interesting group, lying between 

 the Grand and Gunnison rivers, on the western side of the 

 main ranges of Rocky Chain. They also traced and mapped 

 carefully the coal-rocks and overlying formations along the 

 eastern base of the mountains, from the Arkansas River to 

 near the northern boundary of the territory. Mr. Gardner's 

 party measured a new base five and a half miles long in the 

 upper part of the San Luis Valley, about one hundred and 

 twenty miles northwest of the Denver base. The chain of 

 triangles connecting these two bases was completed, and the 

 system extended a hundred miles to the west and sixty miles 

 to the south of the San Luis base. Fourteen stations were 

 occupied, ten of which were over 13,000 feet high. From 

 these the principal peaks over an area of 20,000 square miles 

 were located. Mr. Jackson, after taking many views to il- 

 lustrate the great group of mountains among which the San 

 Juan mining region is situated, in Southwestern Colorado, 

 penetrated beyond them, and, traveling westward along their 

 base, discovered some very interesting groups of ancient ru- 

 ins in the valley and in the faces of the cliffs. These were 

 carefully photographed and described. 



Mr. Wilson and his corps were engaged in working up the 

 great group of mountains about the head of the Rio Grande 

 River. These peaks are undoubtedly the highest in the 

 Rocky Mountains. Twenty-seven of the topographical sta- 

 tions visited by him were over 13,000 feet high. His sur- 

 vey extended westward to longitude 108 15' between the 

 37th and 38th parallels, and including between 5000 and 

 G000 square miles. Mr. Gannett's district lay northward, 

 between the Grand and Gunnison Rivers, and Mr. Marvin's 

 farther north, between the Grand and White Rivers. Both 

 of these surveys extended westward to about longitude 

 108 30', each covering from 5000 to 6000 square miles. Mr. 

 Bechler was engaged around the South Park, and along the 

 eastern slope of the Colorado Front Range. From 18,000 

 to 20,000 square miles of mountain country have thus been 

 topographically and geographically mapped by the Survey, 

 and large collections made by all the parties. 



