Franklin Pierce Lake, also known as Jackman Reservoir,^[1] is a 483-acre (2.0 km²)^[2] reservoir located in Hillsborough County in southern New Hampshire, United States, in the towns of Hillsborough and Antrim. It is named for Franklin Pierce, the 14th president of the United States, who was born in Hillsborough. The lake impounds the North Branch of the Contoocook River and lies within the Merrimack River watershed.

Franklin Pierce Lake
Jackman Reservoir
Franklin Pierce Lake Show map of New Hampshire Franklin Pierce Lake Show map of the United States
Location	Hillsborough County, New Hampshire
Coordinates	43°5′54″N 71°57′10″W / 43.09833°N 71.95278°W / 43.09833; -71.95278
Type	Reservoir
Primary inflows	North Branch Contoocook River
Primary outflows	North Branch Contoocook River
Basin countries	United States
Max. length	2.8 mi (4.5 km)
Max. width	0.7 mi (1.1 km)
Surface area	483 acres (2.0 km2)
Average depth	10 ft (3.0 m)
Max. depth	30 ft (9.1 m)
Surface elevation	764 ft (233 m)
Settlements	Hillsborough; Antrim

The lake is classified as a warmwater fishery, with observed species including rainbow trout, brown trout, largemouth bass, smallmouth bass, chain pickerel, horned pout, white perch, northern pike, bluegill, and black crappie.^[1]