Lost Lake also known as Knop/p/s Pond is a reservoir in Groton, Massachusetts, United States. It was formed from three lakes by the headwaters of Salmon Brook. The southern part of the lake is known as Knops Pond where it is near 30 feet deep. It is stocked with rainbow, brown and brook trout every spring and fall and is home to several species of warm water fish. There is also a boat launch located on the northeastern side of the lake.
|Basin countries||United States|
|Surface area||204 acres (83 ha)|
|Average depth||6 to 8 ft (1.8 to 2.4 m)|
|Max. depth||30 ft (9.1 m)|
Knops Pond is a lake in Middlesex County, in the U.S. state of Massachusetts.Knops Pond was named after James Knapp (or Knop), a pioneer citizen.