From New Mexico Place Names; a Geographical Dictionary
LA BAJADA MESA (Santa Fe). One of the most famous landmarks on the Chihuahua Trail as the descent (and ascent) of the mesa shelf between Santa Fe and Albuquerque. …The freighters wound down the cliff of black basalt for more than a mile, bracing their wagons with boulders when thy stopped, and, after the days of automobile traffic, pouring water into boiling radiators. In 1932, the highway was moved 5 mi. S and E, on a longer but less precipitous grade. La Bajada has always been the dividing line between the section of the state called Rio Arriba “upper river,” and Rio Abajo, “lower or down river,” symbols of divisions in both economy an politics.”
On your way up to Santa Fe take 40 minutes to go see the old road. It’s a special place for multiple reasons. From the Cochiti exit off I-25 go west a few miles to the historic marker and sign for the Tetilla Peak recreation area. Turn north, toward the giant mesa. Here you’ll parallel old 66 and you’ll want to get on the dirt roadbed which means another right turn. This is the pre-1932 route. It crosses the Santa Fe River at on a one-lane wooden bridge after passing a home that looks to have been an early motor court.
This is the prettiest, tiniest town of La Bajada, an inholding of about 80 acres surrounded by Pueblo land. This road continues left and from it you can see the old church and somebody’s new adobe studio. It rejoins the paved highway. You’ll want to turn right past the river and go up the narrow track that takes you to the first of the notorious switchbacks (and a couple of places to pull off and park) at the base of the gigantic looming mesa. If you have the jeep, map, water, gas, time and stamina you can still drive this route up to the top or from the top down. But that’s a whole other picnic.
This is a dividing line, an edge place. It was the only natural break in the entire mesa – a travel corridor since prehistory. It’s a good place to watch the sun set. There are petroglyphs on the basalt. It gets very hot in summer so do it soon.