The island was originally settled in 1673 and served as a seigneury and later an agricultural estate for the Grey Nuns.
It is designated as a protected area under the Natural Heritage Conservation Act of Quebec.
The island’s ecosystem supports a high density of white-tailed deer, which are frequently visible from the main trails.
The refuge is an Important Bird Area (IBA) recognized by BirdLife International for its role in seasonal migration patterns.
The onsite Manoir d'Youville incorporates sections of the original 18th-century stone architecture into its current hospitality operations.
The site hosts a specific 'Pavillon de l'île' which acts as a cultural and environmental interpretive center.
Refuge faunique Marguerite-D'Youville is a 205-hectare protected area situated on Île Saint-Bernard in Châteauguay. The preserve features 8 kilometers of hiking trails through diverse habitats including marshes, woodlands, and orchards. It serves as a significant stopover for migratory birds, with over 200 species recorded in the area. The site is managed by Héritage Saint-Bernard to balance biodiversity conservation with public recreational access. Visitors can access a café located in the historic Manoir d'Youville, a former Grey Nuns convent. The trails provide observation platforms specifically positioned for wildlife photography and birdwatching. Winter activities often include snowshoeing depending on snow conditions and maintenance schedules. The preserve is bordered by the Châteauguay River and Lake Saint-Louis.
The elevated bird blinds along the marsh trail provide the most stable and unobstructed views of local fauna.
Bring high-quality binoculars, as the marsh trails offer excellent long-distance viewing of waterfowl.
Check the official trail status map before arrival, as some paths may close during heavy rain or spring thaw to prevent erosion.
The trails are almost entirely flat, making them accessible for most fitness levels, though path conditions vary by season.
Do not attempt to access the riverbanks outside of designated wooden boardwalks, as the mud can be unstable.
Some trails may be closed during the spring thaw period; the park remains open year-round with varying accessibility for winter sports.
Stay on marked trails to protect sensitive marshland flora; keep dogs on a leash at all times; do not feed the wildlife.
