The Rapid River is similar in its upper portion, but moderates in its final 3 to 4 miles (4.8 to 6.4 km).

It flows generally south, picking up the tributary Evergreen Creek from the east and passing San Juan Hill on the west.

Shortly downstream from the Fourth of July confluence the Beckler is joined from the east by its main tributary, the Rapid River.

[6] In the late 19th and early 20th centuries USGS undertook a massive mapping project in the Cascade Mountains north of Snoqualmie Pass.

Mineral discoveries prompted booms in the late 19th century, especially at Monte Cristo.

Chinook spawning takes places mainly in the Beckler and lower Rapid River.

Coho use shallower side channels of the Beckler River and a few small tributaries.

Adult salmon benefit from a trap-and-haul operation that transports them over a barrier on the lower South Fork Skykomish River.