This extension from the Ohio & Erie Canal known as the Muskingham River Improvement was authorized in 1836. It was designed to give another connection to the Ohio River. This canal brought river traffic to Zanesville and other communities in the Muskingham Valley. It was one of the first complete river canalization schemes in the United States. Two years after construction had begun the commissioners decided to increase the size of the canal so that it could handle the large river boat traffic. They increased the size of the locks from 34 to 36 feet in width and from 150 to 175 feet in length.

The Muskingham extension was completed in 1841 with the Ohio River traffic able to navigate the canal all the way to Zanesville. In 1886 it was ceded to the U.S. Government. After lying derelict after the floods of 1913 it was returned to the state in 1958. The state did repairs to the section from the Ohio River to Zanesville and it is the only area of canal in Ohio that is still used today.

The Muskingham River Improvement connected with the Ohio and Erie Canal by means of the Dresden Side Cut, a cut two miles long from the junction of Webbsport to the Muskingham River . It crossed Wakatomika Creek via an aqueduct and descended to the river through 31 locks. From Dresden to Marietta it was 91 miles with a descent of 125 feet 6inches. There were 11 dams, 5 side-cut canals and 12 locks.

A boat traveling from Marietta to Cleveland too a much shorter route along the Muskingham River Improvement than if they had stayed on the main line.