Several types of karst features related to hot springs are developed in the Ordovician to Mississippian carbonate rocks exposed along both banks of the Arkansas River east of Salida, Colorado. The area is also one of current hot-spring activity. The karst features show a degree of development and morphology which separates them from karst features formed solely by cold groundwater. Part of the difference reflects the solutional agents, H₂S and H₂SO₄, the latter forming where the hydrogen sulfide-bearing hot-spring waters mix with oxygenated groundwater.

The karst features occur in both dolomite and limestone but are much better developed in the latter. The best developed small- and moderate-scale features are present in the Mississippian Leadville Formation.

Individual solution features include shelter caves up to 40 ft (12 m) high and 30 ft (9 m) wide, spongework-type cave development, and ascending water chimneys. Multiple "spongework" caves up to 3 ft (1 m) high occur within a zone 12 ft (3.6 m) thick in one exposure.

The hot-spring solution activity is localized by structure occurring along fractures and bedding planes, and in one place is channeled along a tight syncline. Similarly, it may also produce structure. At one exposure the removal of tens of feet of carbonate rock across an area a few hundred feet wide has produced a synclinal sag and local anticlinal closure at one edge of the syncline.

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