The railroad entered the San Luis Valley by the early 1880s and opened the door for migrating Anglo-Americans. Many emigrants from the East Coast and Midwest brought with them the central passage plan. Two possible structures that might have introduced the plan are either Fort Garland or the Costilla County Courthouse. A classic example is the circa 1890 J.R. Valdez house. The Valdez building is a Late Victorian, one and-a-half story “I” house, with an intersecting centered gable. This structure is one room deep, with a center hallway and ornate wooden porch. Like many of the remaining center passage plans in the San Luis Valley, this house is constructed of adobe and has a symmetrically placed hallway at the facade entrance. Center-passage halls normally are narrower than the other rooms in the building. Typically, builders constructed the hall in a 6-10 feet width. In contrast, rooms were 12-16 feet wide.
Although the center passage plan is often two rooms deep, in the San Luis Valley it more often combined with the Anglo-American “I” house. This form is usually two-rooms wide, one-room deep, and two stories tall. The establishment of commerce and increased agricultural activity resulted in economic prosperity for some families who correspondingly improved their houses and farmsteads. The more prosperous families constructed the center passage plan in the latter part of the 1890s. Consequently, living arrangements in the house shifted from the all-purpose common rooms to specialized rooms (e.g., kitchen, parlor, and bedroom). The central hall ordered the separation of uses of each room. These houses also adopted the other innovations of the era such as pitched roofs with dormers, side gable symmetry, and a one-and-one-half story height. Since the distribution of the central passage houses was limited to the wealthier farmers at San Luis, only a few examples exist.