Having just entered the above in the DB I was reading a little about the history of the mine. Came across what I think is an interesting little snippet.
During late 1901 the Clear Creek mine used twenty Clydesdale horses to move the mined coal from the extreme interiors to the mine opening. Most other camps used mules for this work. The Clear Creek mine was the highest of all of Utah's coal mines, at an elevation of 8,200 feet.
http://utahrails.net/utahcoal/utahcoal-pleasant-valley.php#clear-creek
The past is a foreign country: they do things differently there.