Thanks for the response. From the census the "N.R" is a male, the Sarah his wife. Another researcher has indicated they are probably Neely R., wife Sarah, and daughter Mary Margaret. The name is sometimes referred to as "Asbury R." but this is not correct.

They are thought to have left Missouri heading to Oregon.
They may be related- cousins possibly- to an Ashbel, Sarah Ann, and Margaret who show up on the Fremont Co., Iowa census (with a different name spelling).