Adding the longest headwater tributaries, South Fork Skykomish and Tye River, the length is 62.4 miles (100 km).

The headwaters of the North Fork Skykomish River are located in the Henry M. Jackson Wilderness near Dishpan Gap along the Pacific Crest Trail.

The Wild Sky Wilderness protects tributaries and forests adjacent to the North Fork Skykomish, although not the river itself.

A short ways down from that, the river flows through an even shorter but very twisted and unusually shaped canyon at Bear Creek Falls.

The South Fork average flow of 2,431 cu ft/s (68.8 m3/s) is sourced from a drainage area of 355 square miles (920 km2), compared to the North Fork which has an average flow of 1,216 cu ft/s (34.4 m3/s) from a drainage area of 146 square miles (380 km2).

[7] Glacial loss in the higher portion of the watershed in the Cascades has led to declining streamflow, especially during the late summer.

Consequently, days with streamflow below the threshold necessary to maintain short-term survival of fish in the river has increased.

The interpretive center was built near the site of one of the greatest railroad tragedies in American history, the Wellington Disaster.

[citation needed] The Skykomish River is used for rafting and kayaking, especially around the Index, WA area during the summer months.