The Rio Hondo is a 79-mile-long river in southern New Mexico which begins at the confluence of the Rio Bonito and Rio Ruidoso rivers near the town of Hondo, New Mexico. The river flows eastward through the Hondo Valley in the foothills of the Sierra Blanca and Capitan Mountains, roughly paralleling the route of U.S. Route 70 through the towns of Picacho a…The Rio Hondo is a 79-mile-long river in southern New Mexico which begins at the confluence of the Rio Bonito and Rio Ruidoso rivers near the town of Hondo, New Mexico. The river flows eastward through the Hondo Valley in the foothills of the Sierra Blanca and Capitan Mountains, roughly paralleling the route of U.S. Route 70 through the towns of Picacho and Tinnie. Near the community of Riverside the river passes through a deep canyon before entering the rolling hills west of Roswell.