I found more about the MO&RR Railroad at this site: http://encyclopediaofarkansas.net/encyclopedia/entry-detail.aspx?entryID=3473
It mentions Chicot Co. Monticello and Warren, but is silent regagarding the route from Warren to Camden. Without evidence to the contrary, the proposed route must have skirted Calhoun County, probably to bypass the Moro and Champagnolle creek bottoms.