Paleocene nonmarine mollusca from the Raton Formation, Raton Basin, New Mexico
— Joseph H. Hartman

In 1917, W. T. Lee reported on the only faunule of nonmarine Mollusca so far known from the Upper Cretaceous-Paleocene strata of the Raton Formation of the Raton Basin, New Mexico. The specimens collected by Lee are poorly preserved as goethite-stained steinkems consisting of tine-grained feldspathic sandstone. The taxa recognized include the bivalve Unionidae, gen. & sp. indet. and the viviparid gastropods Viviparus sp. indet. and Campeloma sp. indet. These freshwater fossils were found on the top of the west wall of Dillon Canyon, about 1.6 km above the mouth of Coal Canyon, north of Blossburg, Colfax County, New Mexico. The stratigraphic position of the locality is estimated to be about 195 m above the base of the Raton Formation and approximately 165 m above the base of the Paleocene.