Lathrop State Park covers 1,594 acres of land and boasts two reservoirs — Horseshoe and Martin — covering 320 acres and fed by the Cucharas River from nearby mountains. The park features the unique Walsen Ridge, a volcanic dike located on the northern boundary and formed by volcanic activity during the Eocene and Oligocene periods.
Geologically, Lathrop is framed by the Spanish Peaks and Sangre De Cristo Mountains. The Spanish Peaks, distinct as "stocks,” which are large masses of igneous (molten) rock, formed in a different way than the uplifted Sangre de Cristo Mountains. Notably, the mountains showcase large dikes — intrusive igneous rock formations — that radiate like wheel spokes. Erosion has revealed walls of hard rock, attracting global geologists who've identified over 400 of these remarkable features.