This 350-acre reservation, administered by the Department of Conservation and Recreation, was acquired from the Massachusetts Port Authoriy in the late 1970's and was opened as a public park in 1985. The largest surviving salt marsh in boston Harbor, it showcases plants and wildlife now rare to the Metropolitan area. During the 1600's the marshlands were used for sheep and cattle pasture with the salt marsh harvested for salt hay. By mid 20th century a few homes, businesses and industrial structures and a fuel tank farm were built on filled in marshland as was the Belle Isle trotter track, now Suffolk Downs race track. The Suffolk Downs Open Air theatre was built on the site of the present Belle Isle Reservation. In 1986 a substantial wetland reconditioning program was begun.

The Friends of Belle Isle Marsh, a non-profit (501c3) grassroots environmental organization, was formed in the early 1980's to help preserve the marsh and publicize its importance as an urban natural resource. We believe that protection ultimately depends on public awareness of the value and beauty of this natural resource. Our focus is mainly educational.