COLTON — The headache is over for many northwestern Adirondack commuters.

On Tuesday, state Route 56 reopened to traffic following a nearly two-month closure. The portion of the road between its intersections with Sevey Road and Stark Road was shut down when a large sinkhole was found in the road on March 2. There were no injuries reported when the sinkhole formed.

State Route 56 runs between its southern terminus at its intersection with state Route 3 and its northern terminus with state Route 37 — for a total distance of about 51 miles. The road is the most direct route between Tupper Lake and Potsdam.

During the road closure, a detour that used several state roads went through Paul Smiths, St. Regis Falls, Nicholville, Hopkinton, Converse and Southville was used to form a route between the villages of Tupper Lake and Potsdam. While the was the most direct alternate route, it added about 25 miles in either direction.

The state Department of Transportation said the sinkhole was caused by a 100-year culvert for a tributary to the nearby Raquette River that failed. It was first noticed by a plow driver, according to a report by NCPR, which added that even though the sinkhole was about 6 feet wide at the surface, the a 30-foot surrounding road had collapsed around it.

In a statement announcing the reopening, DOT said crews and contractors replaced the failed culvert with a 13-section precast concrete box culvert that was larger than the old culvert.

“That will enhance safety, improve resiliency and help prevent flooding along this vital travel route,” the DOT stated.

DOT crews and contractors also reconstructed the slope of the roadway and armored the stream channel as part of the repairs.