[1] Willow Creek's watershed covers 787 square miles (2,040 km2) of relatively arid land.

[4] Willow Creek begins at the confluence of its Middle and South forks, slightly north of Ironside and U.S. Route 26.

The creek continues southeast, roughly parallel to the highway, through Jamieson and Willowcreek before reaching Vale.

Above Brogan, as far as the Malheur Reservoir, 41 miles (66 km) from the mouth, the historic stream was dredged and placer-mined for gold and silver.

[7] The creeks also have a population of rainbow trout; catches averaging 9 to 10 inches (23 to 25 cm) are the norm.