This is a closeup of just the people in the bridge picture. The red dots are the three talked about, no indication which is which.
The back of the photo is written by Mary Andrus (William Gordello Worthen's Wife) apparently to her children:
Time - 1930
Large round boulders, that had rolled down the mountain were used. Four head of horses used to turn one over to be shaped for use. Johnson brothers were brought in to shoot the boulders into sizes to be shaped and dressed to be laid up properly.
Company furnished room and board. The rooms were tents with wood floors and sides, tent tops.
Weekends Granpa, your daddy and Uncle Bob Worthen came home in their car, either Uncle Bobs or Daddy's.
The job lasted probably 6-8 months - there were two bridges - the one in the picture is the arched one.
Baby Richard and I stayed at Mohter and Father's home while Daddy was away.