The southern terminus of FM 192 is along the Rio Grande in unincorporated Hudspeth County. From here, the road proceeds northwestward along the river, passing through Quitman and Esperanza before ending at SH 20 at McNary
In 1946, FM 192 was assigned to a route from McNary on US 80
(present-day SH 20) via Esperanza to the Arroyo Balluco, approximately 12.0 miles. In 1949, the highway was extended 13.8 miles further down the river to the Cox School, its present southern terminus.