The forest is located on several small tracts in Carbon, Columbia, Dauphin, Northumberland, and Schuylkill counties.

The sparks of passing steam locomotives ignited wildfires that prevented the formation of second growth forests.

The Pennsylvania General Assembly passed a piece of legislation in 1897 that authorized the purchase of "unseated lands for forest reservations."

[1] The forest is named for Conrad Weiser, an important Pennsylvanian in colonial days, especially known as an interpreter and emissary in councils between Native Americans and Pennsylvania.

Prior to the July 1, 2005 realignment of Pennsylvania State Forest Districts, Weiser State Forest encompassed 17,961 acres (7,269 ha) and District #18 included Carbon, Dauphin, Lebanon, Schuylkill, and the northern parts of Berks and Lehigh counties.