The container is not at the posted coordinates. To get the coordinates, you will need to complete the 5 stage adventure lab called Weatherford's Historic Greenwood Cemetery. Since this Adventure and Bonus is within a cemetery, please do not attempt this one after sunset and be respectful. One of the lab stages is at the posted coordinates.
Weatherford's Historic Greenwood Cemetery Adventure Lab
Each of the 5 stages in the Adventure Lab has a clue to the location of the final for this bonus. Once you complete the Lab cache, you will be able to find and log this bonus puzzle cache. Everything is within the fenced portion of this cemetery and easily walkable.