Colony Shale Oil Project was an oil shale development project at the Piceance Basin near Parachute Creek, Colorado. The project consisted of an oil shale mine and pilot-scale shale oil plant, which used the TOSCO II retorting technology, developed by Tosco Corporation. Over time the project was developed by a consortium of different companies until it was terminated by Exxon on 2 May 1982 a day which is known amongst locals as "Black Sunday".