It is a two-lane, nondivided, full access roadway for most of its entire length, except for portions between Massena and western Franklin County, where the route widens to a four-lane divided highway.

The Redwood–Malone portion was originally part of NY 3 when the first set of posted routes in New York were assigned in 1924.

NY 37, however, continues northward, passing through Redwood before curving northeast as it enters St. Lawrence County.

Roughly 7 miles (11 km) from the county line, NY 37 encounters Hammond, a small village located west of Black Lake.

Past Hammond, Route 37 heads north toward Morristown, where it meets NY 12, the primary roadway along the St. Lawrence River's southern bank west of this point.

[5] East of Fort Covington, NY 37 follows a more southeasterly routing as it separates from the northernmost extents of the state.

[5] The portion of NY 37 from Redwood to Malone was originally part of the Theodore Roosevelt International Highway, an international auto trail connecting Portland, Maine, on the Atlantic Ocean coast to Portland, Oregon, east of the Pacific Ocean.

[6] In the 1930 renumbering of state highways in New York, NY 3 was rerouted to follow its current routing between Watertown and Plattsburgh.

East of the city, NY 37 used less than 1 mile (1.6 km) of its modern alignment before turning south to follow Van Rensselaer Road to Waddington.

During the same time period, NY 37 was rerouted to follow a new bypass around the southern edge of Ogdensburg.

[11][14] The final section, from the hamlet of Raquette River to Rooseveltown, opened to traffic later that year.