Blacks Fork

[3] The river rises on the northern side of the Uinta Mountains in the Uinta-Wasatch-Cache National Forest in Summit County, Utah, as the combination of three streams draining the area around Tokewanna Peak near the Utah–Wyoming border.

Just before the river crosses into Wyoming, it flows into Meeks Cabin Reservoir, which is used for irrigation and flood control.

[5] After entering Uinta County in Wyoming and then flowing out of the reservoir, the river leaves the national forest.

It then flows northeast through unincorporated community of Millburne and along the edge of the census-designated place of Fort Bridger.

The river then meets the Hams Fork from the north on the southwest edge of Granger.