The Smith River drainage is located south of Great Falls in Meagher and Cascade Counties of west-central Montana. The river drains the Big Belt Mountains on the west, and the Little Belt and Castle Mountains on the east. From the confluence of the North and South forks, the Smith River courses about 120 miles through a broad agricultural valley then into 45 miles of spectacular deep limestone canyon country. After leaving the canyon, the river rolls through a valley edged by rolling hills and comprised of grasslands and cultivated tracts.

Approximately 125 tributaries contribute to the Smith River. Besides the 50-mile-long North Forkand 38-mile-long South Fork, Big Birch, Newlan, Rock, Sheep, Eagle, Tenderfoot and Hound Creeks are important tributaries. Several, such as Sheep and Tenderfoot Creeks contribute high-quality water to the Smith’s mainstem and serve as important spawning tributaries for the Smith’s famous wild rainbow and brown trout.