[1] A particular feature of the Valentine is lenticular beds of green-gray opaline sandstone that can be identified in other states, including South Dakota, Nebraska, Kansas, and Colorado.

At the beginning of the Ogallala times, as sediments began washing out from the rising Rocky Mountains into the central plains states, the members of the Pierre Shale[5] and Niobrara Formation outcrop had been largely exposed in their present outcrop range.

The Valentine Formation presents white, buff, gray to gray-green, unconsolidated, fine-to-coarse grained, fluvial siltstone, channel sandstone, and gravel eroded from uplift of the Rocky Mountains as well as locally eroded materials,[7] particularly Niobrara chalk cobbles and chalk sand.

Locally thick beds of volcanic ash are associated with the underlying opaline sandstone Even as discussed above, the term Valentine is not now formally used outside of Northcentral Nebraska, older literature in other states with Ogallala may refer to the name.

[9][10] The Ogallala's opaline sandstone is to be found in Arkansas River gravel at Pueblo, Colorado.