Another from my brother.
This is a school - or was a school - and not a church, but letters spell out 'Witter-Smith Chapel.' There's also a sizable cemetery out back.
Jim figures the building is a hundred to a hundred and twenty years old. A sign says the school, the cemetery and the roadside park are on five acres donated to the Witter School District in 1871 by George W.R. Smith and Simeon Peter Smith. I found reference to the men on a genealogical site. George was Simeon's son. I read that the senior Smith died in 1863 and his son went on to build the schoolhouse some time after 1888, as well as a store and a post office.
I found no reference to a church at the site previous to the construction of the school, but my guess is there was one. If not, I'm at a loss to explain the graves and the chapel designation.