Comparison of leveling surveys carried out in 1934, 1943, and 1958 indicates that the Diablo Plateau region of Trans-Pecos Texas has been uplifted in archlike fashion in relation to El Paso, Texas, on the west and Carlsbad, New Mexico, on the east. Assuming that all movement occurred between 1934 and 1943, the maximum amount of relative uplift measured is 13.0¿3.6cm. Extending east from El Paso, the leveling route traverses the region's basin and range type structure, including the Hueco Basin, the Hueco Mountains, the Diablo Plateau, the Salt Basin, and the Guadalupe Mountains before terminating on the High Plains near Carlsbad. The maximum relative uplift occurs near the eastern edge of the Diablo Plateau, approximately 12 km west of the Salt Basin graben. Only 15 km west of this maximum, the eastwest leveling route passes near an anomalous outcrop of Precambrian rocks and is intersected by a northwest-southeast trending zone of Tertiary intrusives. The pattern of observed uplift correlates well with a positive Bouguer gravity anomaly, and significant crustal conductivity variations have been mapped nearby by geomagnetic surveys. The observed relative uplift is consistent, at least in sign, with the broad aspects of the tectonic evolution of the Diablo Plateau, although geologic evidence of recent activity is limited to some Quaternary fault scarps and entrenched bajadas in the vicinity of the Salt Basin. The region appears to be aseismic at present. The pattern of observed movement, its geological setting, and it geological and geophysical correlations suggest that inracrustal magmatic activity may be causing the uplift, although corroborative heat flow and seismic measurement are as yet unavailable.