Identified in the photo are:
Front Row (seated): Mr. William H. Etsweiler, Science; Miss Barbara J. Gardner, Physical Education; Mrs. Martha L. Riegel, Languages; Mr. Howard L. Hendricks, Supervising Principal.
Back Row (standing): Mr. Howard W. Cunningham, Physical Education; Mr. Wayne L. Hartman, English and Math; Mr. Ragnar F. Hallgren, Geography & English; Mr. Richard W. Knepp, Industrial Arts; Mr. Richard M. Fralick, Geography & English; Mr. Eugene F. Williams, History.
A digital copy of The Susquehannock, 1951, is available on Ancestry.com.
Corrections and additional information should be added as comments to this post.