Route 66 and National Old Trails Road Historic District at La Bajada

Hairpins on the basalt escarpment

La Bajada is the volcanic-capped escarpment southwest of Santa Fe that long divided New Mexico’s Rio Arriba from Rio Abajo. Listed in 2005, the National Register district at La Bajada for Route 66 and the National Old Trails Road covers about six miles of rubble and gravel roadway — early automobile alignments that climbed the roughly 600-foot face — plus associated bridge, retaining walls, and a small tourist-camp complex at the base. Significant dates in the nomination include 1909, 1924, 1925, 1926, and 1931. Areas: transportation and engineering.

Engineering story

Spanish colonial traffic already struggled here on Camino Real routes; American territorial roads improved wagon lines in the nineteenth century. In 1909 the Territorial Highway Commission cut an automobile grade into the basalt cap with dry masonry walls — marketed as a scenic-highway engineering showpiece and soon absorbed into the Ocean-to-Ocean route branded National Old Trails. A 1924 realignment reduced grades and hairpins on the upper slopes. When the federal numbered highway system arrived in 1926, this road became U.S. 66 (and 85). Crews widened turns for Fred Harvey Indian Detours buses the same year and built a timber trestle bridge across the Rio Santa Fe near a 1925 tourist camp and service station. In 1931–32 a gentler alignment three miles southeast replaced this climb; modern I-25 uses that easier corridor. The abandoned 1909 and 1924 grades remain legible as scars and engineered walls on the face of the mesa.

Contributing fabric includes basalt cut-and-fill, ashlar and rubble retaining walls, switchbacks, the timber bridge with wood piers, painted “Santa Fe Campground” rock lettering, and the adobe tourist-camp residence and cabin units (now private residence/storage, deteriorating but plan-readable at documentation).

Visiting carefully

Portions of the district lie on or adjacent to Santa Fe National Forest and private land near the village of La Bajada. This is not a maintained tourist highway. High-clearance and four-wheel drive are often discussed for the old grades; the nomination describes rubble/gravel surface and steep residual grades (including segments historically near 15%). Do not assume passenger-car access. Check current forest and county road status before attempting any segment of the old alignment. The timber bridge and base complex are historic fabric, not a campground you can occupy without permission.

I-25 travelers see the escarpment from the modern highway; that view is free and requires no off-pavement driving. For the historic grades themselves, treat land status, vehicle capability, and weather as hard constraints. Cochiti Pueblo pottery clay sources on lower sedimentary slopes are a cultural resource context noted in the nomination — not a rockhounding invitation. Stay on established tracks; do not cut switchbacks.