It turns out that the photo was a Lunar Orbiter image like you suggested Raoul.
Below is the official caption accompanying the image.

This image shows details of the Alpine Valley, which runs through the Alpes Mountains in the northeastern portion of the Imbrium Basin. This oblique image was taken looking south, with a portion of Mare Imbrium visible at the top of the image. The Alpine Valley is about 10 kilometers wide and is probably a graben, produced by faulting at the time of the Imbrium Basin-forming impact. The valley was subsequently filled by volcanic material, and includes a small rille running down the center of the valley. Similar valleys are occasionally seen at other large impact basins on the Moon.

SteveS