From abstract: In the Sawatch, Mosquito and Front Ranges of central Colorado and the Sangre de Cristo Mountains of south-central Colorado, Tournaisian beds of the Mississippian Leadville Limestone overlie rocks of Early Mississippian and Late Devonian age. In the Sangre de Cristo Mountains in north-central New Mexico, the oldest beds are the Tournaisian (zone 9) Espiritu Santo Formation. In west-central New Mexico, in the Magdalena, Lemitar, and Ladron Mountains, the Kelly Limestone of Tournaisian and Visean age rests unconformably on Proterozoic metamorphic and igneous rocks. This report examines the stratigraphy of this area.