PAWNEE COUNTY, Oklahoma - Pawnee County Sheriff's have issued a Silver Alert for a missing 61-year-old man. 

According to authorities, Elvin Mills Jr. was last seen around noon Sunday leaving a gas station in Preston Oklahoma wearing blue checkered pajama bottoms and a t-shirt with a light weight light blue jacket. 

Mills has chronic obstructive pulmonary disease and did not have his oxygen with him, police said. 

Anyone with information on Mills whereabouts is asked to contact the Pawnee County Sheriff's Department.