A search was under way Tuesday morning for a man reported missing at Mesa Verde National Park in southwestern Colorado.

Mitchell Stehling, 51, of Texas, failed to return Sunday from a visit to Spruce Tree House, according to park officials. When he did not return, his family called rangers for help.

A quick search of Spruce Canyon, Spruce Tree House, Petroglyph Trail and other trails on Chapin Mesa was initiated following the report. Crews were out early Monday morning and expanded the search area on foot, by horseback, and by helicopter. Two dog teams were also assisting in the search. Approximately 30 people searched multiple trails and canyons until late evening.

Crews resumed their search Tuesday morning. They were joined by 20 members of the San Juan National Forest Hot Shots, bringing the total number of personnel involved to 50.

Daily high temperatures at Mesa Verde are in the 90s. The terrain being searched consists of steep canyons and mesa tops at an elevation between 6,500 and 8,000 feet. Mr. Stehling was last seen wearing a brown shirt and hat, khaki shorts and hiking boots. He was not carrying any water or other gear.