Description from www.leighlarson.com:
"A picnic scene near Spokane, Spokane Co., Washington, about 1910. Those Emma Larson identified, as written on the back of the picture, are [left to right]:
Louie Meyer, Lydia Hutchinson, Almo Larson, Ethel Harris, Jannette [sic] Harris and Dave Everson [sic]."
(Spelling is per website, not necessarily handwriting.)
Ethel and Jeanette were sisters, and Jeannette would soon be marrying Dave Emerson. If the photo was indeed taken in 1910, probably the summer, then they would be wed later in October. The spelling of "Everson" is more than likely incorrect, but this author will contact the site owner for verification.
Date of 1 June 1910 is an estimate, assuming the picture was taken in summer.
Credit for photo and information here.
Accessed 3 November 2014.
abt. Jun 1910