Spanish Fort (Sangre de Cristo Pass, Costilla County / Huerfano County, Colorado)

Sangre de Cristo Pass, Costilla County / Huerfano County · Colorado · Spanish colonial period

Quick BriefA Spanish military fort was constructed and occupied in 1819 near Sangre de Cristo Pass in the present U.S. State of Colorado to protect the Spanish colony of Santa Fe de Nuevo México from a possible invasion from the United States. The fort was the only Spanish settlement in present-day Colorado. The adobe structure had a garrison of only six men, who were attacked in 1820 by 100 whites disguised as Indians. The fort was abandoned in 1821 after the Adams–Onís Treaty took effect redefining the border between Louisiana and New Mexico.

Spanish Colonial

History & Significance

Spanish Governor Facundo Melgares ordered construction of the military fort in 1819 to block a possible invasion of Santa Fe de Nuevo México from the United States. The strategic location straddled the pass separating Costilla County from Huerfano County, the Rio Grande drainage basin from the Arkansas River basin—a critical divide between Spanish-controlled territory and American expansion routes.

Though initially occupied by a detachment of approximately one hundred soldiers who patrolled the area in search of Ute Indians and foreigners, the fort proved short-lived as a garrison. Built of adobe with only six men assigned to it, the fort's inhabitants were attacked in 1820 by 100 whites disguised as Indians; one survivor made it back to Santa Fe.

The empty fort was observed by American travelers crossing Sangre de Cristo Pass, with one noting in 1821 that it appeared recently abandoned. The fort was abandoned in 1821 after the Adams–Onís Treaty redefined the international border, placing the pass in newly defined American territory. The fort stands as the only Spanish settlement in present-day Colorado.