The nearly  road has major intersections with RM 1174 and  US 183 at its termini and has short concurrencies with  SH 29 and again with RM 1174 in Bertram. RM 243 passes through a portion of a national wildlife refuge and crosses two forks of the San Gabriel River.
A significant highway has major intersections with RM 1174 and US 183 at its termini, as well as brief connections with SH 29 and again with RM 1174 in Bertram. RM 243 passes through a section of a national wildlife refuge and crosses two tributaries of the San Gabriel River.