A 51-year-old woman fell about 20 feet from a path at Glen Onoko falls in Jim Thorpe, into the river below on Saturday afternoon.
It took about two hours for firefighters to rescue the woman, whose identity was not released.
She was flown to Lehigh Valley Hospital, Cedar Crest.
The rescue operation was under the direction of Jim Thorpe Fire Chief Jarrod Steber.
One of the firefighters who responded, Wayne Nothstein of the Lehighton Fire Department, said someone heard the woman screaming and it was discovered she had fallen.
The incident happened at about 4:15 p.m. in the lower falls. Glen Onoko has three falls at various levels.
Responding with apparatus and manpower were rescue personnel from fire departments in Jim Thorpe, Lehighton, Nesquehoning, Summit Hill, Penn Forest Township, and Lehigh & Lauzanne (L&L) in Lehigh Township.
This is the fourth rescue from the falls this year.
The most serious happened on April 14 when Jesse Michael Crossley, 20, of Catasauqua fell from the upper falls and was killed.
Also responding to Saturday's incident was the Lehighton Ambulance Corps.