Rio Grande - 3. Santa Elena Canyon: Lajitas to Santa Elena Canyon River Access (20 miles) (TX)
Too low for reasonable whitewater trip.
Some people choose to access the river here for "boomerang trips" (paddling upstream to Fern Canyon at low water levels-- generally < 150 cfs), but accessing the river here requires hiking your boat about 250-300 yards through sand (and sometimes through Terlingua Creek, if it is running.)