White Mule Phillips 66 Service Station and Bus Depot at Intersection of Highways 24 and 36 in Monroe City.  

The White Mule Oil Company was organized by the Producers Oil Corporation in 1920, as one of a string of gasoline service stations in Missouri.

Several years later the late Jasper Henderson acquired the Monroe City property, establishing it on a successful foundation. Mr. Henderson continued to be manager of the business until failing health forced him to retire, at which time he deeded the property to his daughters, Mrs. Cecil P. Forsythe and Mrs. Roy B. Meriwether.

On April 17, 1924, after this change in ownership, Mr. Forsythe who had been located in Clarence for a number of years, returned to Monroe City and assumed active management of the company, maintaining this position until his death in 1941.

In September, 1946, the company began transporting their own merchandise.

The office and truck headquarters of the business are maintained at 232 Winter Street, where the first drive-in service station to be erected by the company in Monroe City now stands.