Paved segment 1 The Mountain Loop Highway starts at the eastern end of
SR 92 in Downtown
Granite Falls. Within Downtown Granite Falls, SR 92 is called E Stanley Street and the Mountain Loop Highway is known called N Alder Street. The highway goes north away from Granite Falls and turns east at the point where the road meets the South Fork of the
Stillaguamish River. From there, the road roughly follows the river and intersects some
Forest Routes such as FR 4201, FR 4018, FR 4020, FR 4037, FR 4052, and FR 4059 while traversing the communities of Robe,
Verlot, and Silverton before the river ends. The loop continues and intersects a private road that connects the highway to the Old Monte Cristo Townsite, which is located 4 miles east of
Barlow Pass.
Unpaved segment At Barlow Pass, the Mountain Loop Highway goes north, and becomes unpaved Forest Route 20 or FR 20. Shortly after becoming unpaved, FR 20 starts to follow the
Sauk River towards Darrington. FR 20 goes northward past Bedal, and it becomes paved again at the new Whitechuck bridge (approximately mile marker 44). seen from designated pullout along the highway
Paved segment 2 From Whitechuck, the Mountain Loop Highway continues north along the Sauk River. On the opposite side of the river, the N. Sauk River Road (Forest Route 22) parallels the route of the Mountain Loop Highway. The loop enters
Darrington, where Railroad Avenue splits from the highway to become a short
bypass to the eastern end of the highway. The highway ends at
SR 530. ==History==