Mystery people left tidbits in a book

Found these 2 1/2" by 4 1/2" negatives in an old math book. From the letter and inscription in the book, I think these are Marg and F.C. Van Wormer.

Photographer:
saeledbetts
Uploaded:
2011-04-26
Tags:
1940s book found mystery negatives people
City:
Grand Canyon?
Country/region:
United States
Year:
1957
Time:
morning
Albums:
The VanWormers
More photos by saeledbetts