Glenmere Lake is a colonial mill pond

Mill pond

A mill pond is any body of water used as a reservoir for a water-powered mill. Mill ponds were often created through the construction of a mill dam across a waterway. In many places, the common proper name Mill Pond name has remained even though the mill has long since gone...

 or reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

 located in Orange County, New York

Orange County, New York

Orange County is a county located in the U.S. state of New York. It is part of the Poughkeepsie–Newburgh–Middletown, NY Metropolitan Statistical Area and is located at the northern reaches of the New York metropolitan area. The county sits in the state's scenic Mid-Hudson Region of the Hudson Valley...

, USA. It is New York State's largest and virtually last habitat of the Northern Cricket Frog (Acris crepitans), listed as endangered by the New York State Department of Environmental Conservation. The lake is threatened by both private and municipal development.

The lake is part of the greater Orange County-owned Glenmere Preserve, one of the largest wild areas in Orange County. Glenmere Lake is the most biologically diverse natural feature of Orange County, with hardwood swamp, shale ridgelines, wide marsh, mossy bogs, vernal pools and an open-water reservoir. Such biodiversity, present in New York’s fastest-growing county, underscores the critical nature of Glenmere’s unique habitat. The Glenmere Reservoir lands are home to Bald Eagle

Bald Eagle

The Bald Eagle is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle...

s, six species of hawk

Hawk

The term hawk can be used in several ways:* In strict usage in Australia and Africa, to mean any of the species in the subfamily Accipitrinae, which comprises the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter genus includes goshawks,...

 and six of owl

Owl

Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...

. Endangered plant and animal species inhabit the Glenmere lands- in fact, New York State’s largest and virtually last population of endangered Northern Cricket Frogs inhabits the entire parcel.

Glenmere straddles Orange County’s two largest Hudson River

Hudson River

The Hudson is a river that flows from north to south through eastern New York. The highest official source is at Lake Tear of the Clouds, on the slopes of Mount Marcy in the Adirondack Mountains. The river itself officially begins in Henderson Lake in Newcomb, New York...

 watershed basins: The Wallkill

Wallkill River

The Wallkill River, a tributary of the Hudson, drains Lake Mohawk in Sparta, New Jersey, flowing from there generally northeasterly to Rondout Creek in New York, near Rosendale, with the combined flows reaching the Hudson at Kingston....

, on its western side, and the Moodna

Moodna Creek

Moodna Creek is a small tributary of the Hudson River that drains eastern Orange County, New York. At 15.5 miles in length from its source at the confluence of Cromline Creek and Otter Kill west of Washingtonville, it is the longest stream located entirely within the county.Despite its small...

, on its east (Represented by its westernmost tributary, the Black Meadow creek

Black Meadow Creek

Black Meadow Creek is a tributary of the Otter Kill in Orange County, New York, in the United States. Via the Otter Kill, it is part of the Moodna Creek watershed, flowing onward to the Hudson River, in one of New York State's most biodiverse natural areas. Home to 13 species of salamander as well...

) . The Glenmere Reservoir Lands include a "watershed ambiguous zone" where small brooks split off into either watershed. The lake and associated county lands comprise sections of the towns and villages of Warwick

Warwick, New York

Warwick is a town in Orange County, New York, United States. The population was 30,764 at the 2000 census. The 2007 census population estimate is 32,669.The Town of Warwick is located in the southwest part of the county...

, Chester

Chester (town), New York

Chester is a town in Orange County, New York, United States. The population was 12,140 at the 2000 census. The town is named after another city in Great Britain...

, Sugar Loaf

Sugar Loaf, New York

Sugar Loaf is a hamlet in Orange County, New York, United States. It is located in the Town of Chester.-History:Sugar Loaf, New York was founded in the 1740s as a waypoint along King's Highway, providing supplies and horses to travelers....

 and Florida

Florida, Orange County, New York

Florida is a village in Orange County, New York, United States. The population was 2,757 at the 2007 census estimates. It is part of the Poughkeepsie–Newburgh–Middletown, NY Metropolitan Statistical Area as well as the larger New York–Newark–Bridgeport, NY-NJ-CT-PA Combined...

.

The 1912 Glenmere mansion

Glenmere mansion

The Glenmere mansion, overlooking Glenmere Lake, approximately 50 miles northwest of New York City in Orange County, New York, was built by New York City real estate developer Robert Wilson Goelet in 1911, on the grounds of his sprawling estate in Sugar Loaf, a hamlet of the town of Chester, New...

 still overlooks the reservoir.

Studies of the lake and its associated periphery are performed by the educational non-profit Glenmere Conservation Coalition.