Abstract of Drummond, C. N., B. H. Wilkinson, K.C Lohmann, G.R. Smith. 1993. Lacustrine isotopic record of late Miocene topography and hydrology in the southern Rocky Mountains. Palaeogeogr., Palaeoclimatol., Palaeoecol. 101:67-79.

Depleted O-18 in the Miocene Camp Davis lacustrine limestone, Wyoming, indicates elevations up to 2300m higher than present or multiply fractionated sources of precipitation from large lakes in the prevailing wind paths from the northwest.