Delaware Water Gap (probably)
This photo was probably taken along the Delaware River near the Delaware Water Gap on the Pennsylvania/New Jersey border.
In the right background, you can see the flat-topped ridge sloping sharply down toward the river gap. This is the characteristic profile of Mount Tammany (on the New Jersey side) or Mount Minsi (on the Pennsylvania side) as viewed looking north/northeast along the river bend.
The wide, calm stretch of water bordered by dense marsh grasses (cattails) and lush riverbank vegetation matches the low-lying shoreline areas near Portland, Shawnee on Delaware, or Minisink Hills along the Pennsylvania side of the river.
The group is standing on the Pennsylvania shore of the Delaware River, facing north towards the entrance of the Delaware Water Gap.