It flows about 30 miles (48 km) generally southeast past Fitchburg, and joins the South Nashua River,[3] shown on USGS topographic maps as the main stem of the Nashua River,[4] about 5 miles (8 km) below its issuance from the Wachusett Reservoir.

"[5][6] The Nashua River was heavily used for industry during the colonial period and the early years of the United States.

A broad conservation buffer was created along about half the river and its two main tributaries.

[7] Recovery has sparked recreational use of the river at places like Mine Falls Park in Nashua.

The legislation was sponsored by Rep. Niki Tsongas (D, MA-3), supported by the Nashua River Watershed Association[10] and The Wilderness Society.