The Huaynamota drains a basin of 17,265 km2, which covers parts of the states of
Nayarit,
Durango,
Jalisco, and
Zacatecas. The basin extends from 21° 24’ 36.82” to 23° 25’ 3.26” N and 104° 30’ 34.03” to 103° 24’ 26.73” W. The basin is mountainous, ranging in elevation from 216 to 3,148 meters. The basin is bounded on the east by the
Sierra los Huicholes, which separates it from the
Bolaños River basin. The Sierra de Valparaiso bounds it on the north. The basin of the
San Pedro Mezquital River bounds it on the west and northwest. The
Sierra Alicia bounds it on the south. The main tributaries of the Huaynamota are the
Jesús María River, which flows from the north, and
Atengo River, also known as the Chapalagana, which joins from the east. The basin of the Jesús María covers 5,185 km2. The Atengo River drains a basin of 12,080 km2. The Atengo's main tributaries are the Huajimic, which joins the Atengo from the south and drains the east slope of the Sierra Alicia and west slope of the
Sierra Pajaritos, and the
Camotlán, which drains the east slope of the Sierra Pajaritos and the southwestern Sierra los Huicholes. The Huaynamota empties into
Aguamilpa Reservoir, created by construction of the Aguamilpa Dam on the Río Grande de Santiago 25 km below its former confluence with the Huaynamota. ==Climate==