The main branch is formed by the confluence of the North Fork and South Fork in eastern Meagher County, 25 miles east of Martsindale, north of Martinsdale Resevoir, and just west of Meagher County's border with Wheatland County.
The main branch is formed by the confluence of the North Fork and South Fork in eastern Meagher County of Martsindale. This was north of Martinsdale Resevoir, and just west of Meagher County's border with Wheatland County. This was 25 miles east.