The surficial geology in its vicinity consists of alluvium, surface mining land, coal dumps, fill, Wisconsinan Till, and bedrock containing sandstone and shale.

It flows south-southeast and south for several tenths of a mile through a valley near Brace Brook Road before entering Clinton Township.

The stream then flows south-southeast for several tenths of a mile before entering another valley and receiving an unnamed tributary from the left.

[1] Brace Brook joins the Lackawanna River 36.96 miles (59.48 km) upriver of its mouth.

[1] Brace Brook drains a portion of the western side of the Moosic Mountain Ridge.

[7] The surficial geology along the stream in its lower reaches mainly consists of alluvium, surface mining land, coal dumps, and fill.

Further upstream, the surficial geology in the stream's vicinity mainly consists of Wisconsinan Till, but there are patches of alluvium and peat bogs near the Brace Brook Reservoir.

Bedrock consisting of sandstone and shale lines the sides of the stream's valley in its middle reaches.

[4] In the early 1900s, the supervisors of Clinton Township, Wayne County requested permission to construct a bridge across the stream on a new road approximately 2 miles (3.2 km) northeast of Forest City.