At Pecos Falls, 29 mi (47 km) north of Pecos, New Mexico.

35.976111, -105.558056

One and a half mile south of the high Bridge which cross the Pecos on US 90.

The Pecos River originates in north-central New Mexico with its headwaters on the eastern slope of the Sangre de Cristo mountain range in Mora County north of Pecos, NM, at an elevation of over 12,000 feet (3,700 m).

The river flows southward into Texas and continues for 926 miles (1,490 km) before reaching the Rio Grande near Del Rio.

Its drainage basin encompasses about 44,300 square miles

New Mexico; Pecos, Santa Rosa, Fort Sumner, Roswell, Artesia, Carlsbad

Texas: Lantry, Pecos,

New Mexico: Aqua Negra, Hondo, Felix, Penasco

Texas: Black