ABSTRACT: The Ordovician Manitou Formatton crops out between Aspen and Minturn on Üıe westflank of the Sawateh Range to western Colorado. In this study the Manitou Formation is divided, from baseto top, in to three Utofacies units: intraclastic conglomerate, sandy dolomite, dolomite and chert Theintraclastfe conglomerate Uthofacies consists of dolomite-pebble conglomerates and contains ripplemarks, mud-cracks and horizontal feeding tracks of animals on the bedding planes. The intraclastic cong«lomerate lithofacies was deposited in an Interttdal environment The sandy dolomite uthofacies is represented by dolomites, stromatoliHe banding, and large amounts of detrital meterial, indicating a supratidaJenvironment. The dolomite and chert lithofacies is composed of dolomites and chert nodules, and chert lenses.Large numbers of ecMnodernis, brachlopods and trilobites and chert nodules* and chert lenses. Largenumbers of echinoderms, bracMopods and trilobites can be recognized İn places where recrystallizatton anddolomitizatton is not extensive, The dolomite and chert Uthofacies was deposited in a subttdal environment, Inthe Aspen-Mmturn area the original depositional textures of the Manitou Formaton has been altered completelyby recrystallization and dolomitizatioii