Site Description and Location
Triangle Prairie (also known as, Altiman Road North Prairie) is 7.04 hectares / 17.39 acres and composed of 13 different lots. Altiman Road North Prairie is located on the west shore of Walpole Island First Nation along the St. Clair River. Access is from Nahdee Lane.

Significant Natural Features
This natural area was identified, in 1985-87 through the Life Sciences Inventory of the Prairies, Savannahs and Woodlands of the Walpole Island First Nation, as a significant tallgrass prairie remnant.

This area supports significant open mesic and wet-mesic prairie, and is considered to be one of the most significant natural areas on Walpole Island. A virgin mesic prairie with an open structure, dominated by little bluestem grasses.

Many rare species, including the best Canadian population of Gattinger's Agalinis and Skinner's Agalinis, both of which are abundant here.

Pink Milkwort and Fimbristylis spadicea are locally abundant here. Fimbristylis and Skinner's Agalinis are not known in Canada outside of Walpole Island.