Tierra Amarilla is an unincorporated community near the Carson National Forest and is the county seat of Rio Arriba County. Tierra Amarilla is Spanish for yellow soil. The name refers to clay deposits found in the Chama River Valley and used by Native American peoples.
The area served as a trade route for peoples in the present-day Four Corners region and the Rio Grande Valley. Navajos later used the valley as a staging area for raids on Spanish settlements along the Rio Grande. Written accounts of the Tierra Amarilla locality by pathfinding Spanish friars in 1776 described it as suitable for pastoral and agricultural use. The route taken by the friars from Santa Fe to California became the Spanish Trail. During the Californian Gold Rush the area became a staging point for westward fortune seekers.
There are still elements of "Wild West" thinking here, as evidenced by a rancher's creative way of letting tresspassers know they are not welcome.
Tierra Amarilla does not follow the urban planning principles of the Laws of the Indies.
These rules are part of a body of 148 regulations configuring any settlement according to the rule of Spain and its colonies. The Laws specify many details of towns. A plan is made centered on a Plaza Mayor (main square) of size within specified limits, from which twelve straight streets are built in a rectilinear grid.
The directions of the streets are chosen according to the prevailing winds, to protect the Plaza Mayor. Most townships founded in any part of the Spanish Empire in America before the various parts became independent were planned according to the Laws.
Today, the area is used for small farming, cattle and horse ranching.