The Town of Manassa is the Statutory Town that is the most populous municipality in Conejos County, Colorado, United States. The town population was 991 at the 2010 United States Census.This small town is surrounded by farms and ranches, with a small amount of residential development on its outskirts. A mostly agricultural community, there are few business establishments in the town. A small-town feel abounds with no traffic control signals or stop lights.The U.S.