This ecological reserve covers the whole of Garth Island, located on the territory of Bois-des-Fillion. The area is 17.23 hectares, with approximately 90% being a flood zone.

This reserve is meant to permanently protect tree groups that are rare to the region, the hackberry and maple hickory-silver stand, the black maple, and the three-leaf staphyloma threatened species. The island is accessible to visitors through guided excursions during the summer and by reservation only.

Photo: Google Street View, Francois Langlois