From the Annals of the Temblors – In 1931, an earthquake in Texas shook the ground near Valentine in Jeff Davis County. The quake measured 6.5 on the Richter Scale. No casualties were reported, but the quake caused damage to almost every wooden structure building in Valentine. The local school building was damaged beyond repair. There were also reports of landslides as far away as the Guadalupe Mountains. The Valentine temblor remains the most powerful recorded earthquake in the entire state.
Figure showing felt area and Modified Mercalli Intensities experienced by Texans from the Valentine earthquake from www-udc.ig.utexas.edu.