In New York, Juncus trifidus is restricted to the high peaks region of the Adirondacks and the Shawangunks in the southeastern part of the state.

This species occurs in Europe, Asia, and North America. In North America it grows from Greenland and northern Quebec south to the high mountains of northern New England and the Adirondacks, disjunct in the Shawangunks in southeastern New York, and disjunct to the highest mountains of the southeastern United States (West Virginia, Virginia, and North Carolina) (Brooks and Clemants 2000, Weakley 2006).