It is crossed by the Ashland Mill Bridge in Griswold, Connecticut, a bridge which is listed on the U.S. National Register of Historic Places.

[3]: 227  It has a public beach, kayak/canoe boat launch as well as camping and picnic facilities.

The source of the Pachaug River is a small "stream-like" section in Exeter, Rhode Island north of and draining into Beach Pond, a large impoundment split between Voluntown, Connecticut and Exeter, Rhode Island.

The Pachaug River was used by the Mohegan Indians, who constructed stone weirs to direct the water flow and funnel fish to the center of the stream for trapping.

[6][7] In the 1970s, a plan was drawn up to pump 7.5 million gallons of water a day from the river into the Rattlesnake Brook, which in turn would feed the Broad Brook.