Coupler Run is a long 2nd order tributary to Montgomery Run in Clearfield County, Pennsylvania. This is the only stream of this name in the United States.
Coupler Run rises about 5 miles east-southeast of Rockton, Pennsylvania, and then flows north and northwest to join Montgomery Run about 3 miles northeast of Rockton.
Coupler Run drains of area, receives about 46.2 in/year of precipitation, has a wetness index of 452.11, and is about 95% forested.