The marsh is on the south side of MA-116 (West Main Street) and east of Plainfield Pond.

West Mountain Wildlife Sanctuary is situated within the watershed of the federally designated Wild and Scenic Westfield River. It's part of one of the largest aggregations of conserved land in Massachusetts. 

The sanctuary provides valuable habitats for moose, black bears, otters, fishers, and bobcats as well as habitats for some state-listed rare plants and animals and nesting sites for threatened ground-nesting birds.

• In an area characterized by rugged hills with forests of northern hardwoods.
• Spring ephemeral wildflowers along the trails.
• A spruce-fir forest, a forest type typically found farther north.