Named for research biologist, educator, and consummate naturalist, Howard L. Mendall, this is one of the few significant saltmarsh habitats in all of Penobscot Bay. Mendall Marsh, as it is often referred to, is formed by the confluence of the north and south branches of Marsh Stream and the Penobscot River. The marsh at one time was an important terminal for shipping granite quarried from nearby mountains. Today, the marsh is dominated by sedges and other grasses and is a popular spot for waterfowl hunting. U. S. Route 1A follows the western edge of the marsh.
The expansive patches of saltmarsh sedge provide excellent habitat for a large breeding population of Nelson?s Sharp-tailed Sparrows. American Black Ducks are found here in good numbers during the nonbreeding season.
Despite having a conservation owner, this site is easily accessible and public dumping (e.g., domestic trash, construction debris, white goods, etc.) is an annoyance to managers. U. S. Route 1A is a constant presence through noise, roadside trash, and introduction of invasive species. Purple Loosestrife is present in a few locations and non-native Phragmites occurs in sections along Route 1A. Contaminants in the Penobscot River (mercury, dioxins, heavy metals) are undoubtedly present in the marsh as well, but the level to which local bird life is affected is yet unknown.
The marsh is owned and managed by the Maine Dept. of Inland Fisheries and Wildlife and is accessible year round from U. S. Route 1A, about one mile south of Frankfort. A boat launch and an old granite pier provide fine views of the marsh.