If you are not lucky enough to own your own aircraft, your closest choices for airports are Midland-Odessa and El Paso. The distance to Marfa from both of these airports is 180 -190 miles.
Consult Your Map
We are 37 miles up FM 170 from Presidio, Texas. FM 170 rises and falls, twists and turns along the Rio Grande. It's austere beauty can be captivating -- but please take care! This part of Presidio County is open range, and it is not uncommon to crest a hill and find an unconcerned cow in the road! Please plan on over an hour to reach Ruidosa, plus another half hour on Hot Springs Road, the gravel road that takes you the final 7 miles up from FM170 to the springs. The road is a bit rough, but high clearance or 4WD is not necessary.
Options from Marfa
 Via FM2810 and Pinto Canyon Road 53 miles, 2 hours 15 minutes High Clearance / 4WD necessary OR  Via US-67 S and FM170 94 miles, 2 hours 19 minute