The current Monarch Pass is the third location on the Continental Divide to carry that name. The
Original Monarch Pass is just northwest of the present pass. A road traversing this first Monarch Pass was constructed in 1880 and served as an important wagon and stage road connecting the town of South Arkansas City (later
Salida) on the east side with booming mining camps and the city of
Gunnison on the west side. In 1922, the road was improved and rerouted to better accommodate motor vehicles. The new road, today known as
Old Monarch Pass, crossed the divide northwest of the present pass. It remained an important unpaved crossing of the divide until 1939, when yet another highway realignment was made to accommodate increased traffic. During the 1930s, efforts were underway to complete the newly designated
U.S. Route 50 across America. In Colorado, one of the more difficult challenges was the routing of the new highway over the Continental Divide. It was clear new road would need to be constructed, but there were three competing options for where to cross the divide.
Marshall Pass and
Cochetopa Pass, both to the south and at lower elevations, were under consideration as was Monarch Pass, the more direct route between Salida and Gunnison. In September 1938, state engineer Charles Vail decided to utilize the Monarch Pass route, but with significant reconstruction and rerouting to reduce grades, minimize tight curves, and keep the roadbed up on sunny slopes where winter snow would be easier to manage. To achieve these objectives, the road was rerouted over what was then called Agate Pass or Agate-Monarch Pass, which now serves as the third Monarch Pass. The new U.S. Route 50 over the divide was completed, except for paving, in November 1939, and the new pass was initially designated ‘’Vail Pass’’. Area residents objected to the name, and in December 1939, Governor
Ralph Carr officially designated the new pass as ‘’Monarch Pass.’’ Soon thereafter, a newly constructed pass on
U.S. Route 6 crossing Colorado farther to the north was named
Vail Pass. == Weather station ==