Here is their marriage information. It may help to know Grace's last name was Humphrey, not Umphrey.
ID Number 13970
Grooms First Name George W.
Grooms Last Name ARD
Grooms Residence Clementsville
Brides First Name Grace F.
Brides Last Name Humphrey
Brides Residence Canyon Creek
County of Record Fremont Co., Idaho
Place of Marriage St. Anthony
Date of Marriage 1 Feb 1913
Volume 3
Page 28

Maybe this is his son too?

ID Number 35183
Grooms First Name George Francis
Grooms Last Name ARD
Grooms Residence
Brides First Name Belva Jeanne
Brides Last Name SPILLMAN
Brides Residence
County of Record Fremont Co., Idaho
Place of Marriage St. Anthony
Date of Marriage 26 Nov 1941
Volume 4
Page 479