Greater Saint Mark was organized in as Saint Mark AME Church in 1886 and the present sanctuary was built in 1961, during the pastorate of Rev. W. L. Brown. An old cornerstone saved by the congregation indicates an earlier church was built in 1889, during the pastorate of Rev. M. R. Wilson.
There are a lot of churches for the small town of Clyo, but I don’t remember one with this name. There are none listed on this website.
I think there’s one in Clyo.