Widespread Deep-Seated Gravitational Slope Deformations Across the Sawatch Range, CO

This presentation introduces the first range-scale Deep-Seated Gravitational Slope Deformation (DSGSD) inventory in North America, focusing on the Sawatch Range of central Colorado. Through geomorphic mapping, field campaigns, and InSAR displacement analysis, we identified and characterized 39 previously unreported DSGSD. We analyzed this inventory to reveal the governing mechanisms that condition slopes for DSGSD development and to compare it with the global DSGSD inventory. Site-specific surveys of the South Mt. Massive and Mt. Jones DSGSDs result in interpretive cross sections that relate surface morphology to subsurface geological parameters and highlight how Sawatch DSGSDs form and evolve in unique ways. Furthermore, we discuss the implications of this work to the broader context of Rocky Mountain DSGSD.

 Widespread Deep-Seated Gravitational Slope Deformations Across the Sawatch Range, CO, Evans (2026), USGS Landslide Hazard Seminar, 09 September 2026.