Grassy Island

Grassy Island is a river island located in the Detroit River north of Grosse Ile, surrounded by steep earthen embankments on all sides. The island covers approximately 72 acres and sits between industrial areas and other waterways in this part of the river.

The island was first recorded by French explorers in 1796 as Ile Marecageuse when it measured only about 6 acres. Over time it grew substantially through sediment disposal operations that began in the 1960s.

The island formed part of the Wyandotte National Wildlife Refuge in 1961, marking the beginning of federal environmental protection efforts in the Detroit River.

The island can only be reached by boat since there are no bridges or regular ferry services to it. Most visitors cannot access the island due to soil contamination and environmental restrictions in the area.

Between 1960 and 1982 the island was used as a disposal site for millions of cubic meters of sediments from the River Rouge. These sediment deposits essentially doubled the island's original size and permanently altered its shape.

Location: Wyandotte

GPS coordinates: 42.22250,-83.13472

Latest update: December 21, 2025 16:05