The Old Fort was originally in Pagosa Springs
This is unknown artists drawing of Fort Lewis at Pagosa
General Phil Sheridan made a tour of inspection of the west in 1879. After passing through Animas City (town site now part of northern Durango) and Fort Lewis, he continued on to Santa Fe. After returning East, he recommended that Fort Lewis be moved to a more central location.
On September 29, 1879, the Meeker Massacre occurred. It was feared that the Northern Utes, led by Chief Ouray, would join with the Southern Utes in a war against the government. As a result, troops from Fort Lewis made a hurried march from Pagosa Springs to Animas City. The 600 plus men remained there until January 1880.
Soon after their return, it was decided that Fort Lewis should be moved to a location that would better protect settlers. General Buell chose a site on the Mancos river while General Thomas H. Ruger decided that a fort on the LaPlata River would be more suitable.