A few of the originals made sense because that’s where the people were. Some made sense because of geography. And some contained vast areas of land because no one knew what to do with it yet.
County boundaries have changed often since the Territory and the State of Colorado were created. Beginning with 17 counties in 1861, Colorado had increased to 64 by the year 2001, but, beginning with two, the San Luis Valley would be split into six in its first half century.
The Thirty-sixth Congress authorized a temporary government for the Territory of Colorado on February 28, 1861, with boundaries that remain very close to the originals, an exception being some tweaking of our nearby Thirty-seventh Parallel. Members of the territory’s first legislature, who were elected that summer, convened on September 9 and established the counties on November 1, 1861.
Two of these were Conejos and Costilla Counties in the San Luis Valley, with the temporary names of their respective county seats being Guadaloupe and San Miguel. Within a few short days, the names of these two counties seats were changed to Conejos and Costilla.
(San Miguel, I believe, was the name of the church in the village of Costilla, then in Costilla County although a survey placed the town in New Mexico in 1867. Both counties lost land to New Mexico at the time of the survey.)
Jurisdictions of the original counties often were large. In the case of Conejos County, it included the area south and west of the Rio Grande River in Colorado and west to the Utah border, while Costilla County took in everything north and east of the Rio Grande within the San Luis Valley and the surrounding mountain ranges.
Realignment of county boundaries soon began, however. Competing interests of early colonists, merchants, ranching and farming, politics, and administration of the Indian agency resulted in a move for a new county in the northern portion of Costilla County.
As a result, Saguache County was designated on December 29, 1866. Its southern boundary cut straight across Costilla County approximately along today’s Colorado 112, and the northwest boundary extended across Cochetopa Pass into land that had formerly part of Lake County, thereby including the erstwhile Indian agency. A straight, north-south line ran along the west side of Saguache County.
Before long, Conejos County also lost important real estate due to mining activity in the San Juan country, particularly Summitville. On February 10, 1874, Rio Grande County was carved from land south of the Rio Grande, plus adjacent land in Costilla County abutting Saguache County. A peculiar triangular chunk of Rio Grande County also jutted up into Saguache County.
In the 1870s the Land Office was established. As a result, surveyors, county administrators, and courts were providing steady work for a lot of folks in the Valley. Moreover, by the end of that decade railroading brought major demographic and economic changes and railroad rights-of-way, wherever they went.
What remained of the original Conejos and Costilla Counties by then was becoming smaller and smaller. In fact, most of Conejos County west of the Continental Divide had been lopped off since 1874.
A few years later, mining at Creede resulted in the creation on March 27, 1893, of tiny but all-important Mineral County, whittling land from Hinsdale, Rio Grande, and Saguache Counties. An odd nubbin of land remained attached to northwest Rio Grande County in the area of Embargo Creek.
Although the town of Alamosa had quickly become the center of commerce, transportation, and population, the establishment of the last county did not occur until 1913 on March 8. Indebtedness to Conejos County complicated the creation of Alamosa County for a few years.
The new county acquired Costilla County’s land north of the original Sangre de Cristo Land Grant up to Saguache County and west to Rio Grande County. And Conejos County lost valuable land south of the Rio Grande, west to Rio Grande County and south of Road 15.
Thus, the two original counties in the San Luis Valley, Conejos and Costilla, had been severely diminished from their original size in a century, but they still had a proud heritage for consolation.