The Prairie du Rocher La Guiannee visits the site to play period music and sing. In a traditional celebration dating back to 1722, the La Guiannee singers will visit houses and Fort de Chartres in the early French town of Prairie du Rocher and sing for the residents. As part of the tradition, the residents provide refreshments for the singers at each stop. It is cosponsored by Les Amis du Fort de Chartre, Fort de Chartres State Historic Site, and the Prairie du Rocher La Guiannee Society. The site is operated by the Illinois Historic Preservation, part of the Illinois Department of Natural Resources.. This agency protects the state’s historic resources, which contribute to education, culture and the economy. Illinois Historic Preservation sites include ancient burial mounds, forts and buildings erected by settlers, and homes connected to famous Illinoisans.