Along the north banks of the Niobrara River in northern Nebraska, the pink of the Rosebud Formation is commonly seen with many seeps, trickles, and waterfalls emitting from the Ogallala Aquifer in the overlying Valentine Formation[1]
^ ab"Geologic Formations". Niobrara National Scenic River. National Park Service. Retrieved 2024-02-24. A finer-grained siltstone, the reddish-hued Rosebud forms the "floor" of the Ogallala aquifer. Water cannot seep into the rock as easily as it can in the Valentine, and a stream cannot cut down through it as quickly. There are more than 200 spring-fed waterfalls found along the scenic portion of the river, and most are "held up" by the Rosebud formation.
^ ab"Geologic Unit: Rosebud". National Geologic Database. Geolex — Significant Publications. United States Geological Survey. Retrieved 2024-02-24.