The Tuya River is a major tributary of the Stikine River in northwest part of the province of British Columbia, Canada. From its source at High Tuya Lake in Tuya Mountains Provincial Park just south of Ash Mountain, the highest peak of the Tuya Range, the Tuya River flows south about 200 km (120 mi) to meet the Stikine River in the Grand Canyon of the Stikine. The Tuya River's main tributary is the Little Tuya River. The Tuya River divides the Tanzilla Plateau on the east from the Kawdy Plateau, to the northwest, and the Nahlin Plateau, to the southwest. All three are considered sub-plateaus of the Stikine Plateau. The Tuya River's watershed covers 3,575 km2 (1,380 sq mi), and its mean annual discharge is estimated at 36.9 m3/s (1,300 cu ft/s). The mouth of the Tuya River is located about 24 km (15 mi) northeast of Telegraph Creek, British Columbia, about 67 km (42 mi) southwest of Dease Lake, British Columbia, and about 210 km (130 mi) east of Juneau, Alaska. The Tuya River's watershed's land cover is classified as 35.7% shrubland, 31.4% conifer forest, 14.0% mixed forest, 7.2% herbaceous, and small amounts of other cover.