The name may be derived from a member of the families of John and Alexander O'Bar who settled in Fayette County possibly before 1836. Throughout its course the stream flows over shallow to moderately deep sandy loam overlying dense clay subsoils. The area is rated as poor to fair for agriculture but produced good crops of cotton during the period 1870 to 1950 and is used as pasture for cattle.
Wildlife habitat is good.
The Texas State Historical Association, 1997,1998,1999.