A reversed seismic-refraction profile was recorded in the Colorado Plateaus province from Hanksville, Utah, to Chinle, Arizona. The velocity of Pg is 6.2 km/sec, and the velocity of Pn is 7.8 km/sec. Waves identified as reflections indicate that an intermediate layer in the crust has a velocity of approximately 6.8 km/sec. Thickness of the crust is 43 km at Chinle and 40 km at Hanksville. The Pn velocity in the Colorado Plateaus province is the same as that in the Basin and Range province, but is significantly lower than Pn velocity in the High Plains of Colorado.