[3] The Timberline Trail was constructed in the 1930s by the Civilian Conservation Corps, the majority of their work taking place in the summer of 1934 at a cost of $10,000.

The trail is rerouted periodically due to washouts and to avoid sensitive high altitude and alpine meadows.

It has a handful of informal campsites for backpackers, although camping is permitted anywhere outside the meadows and at least 200 feet (61 m) from water bodies.

There are several hazardous river and stream crossings, especially on the west side of the mountain and at the landslide-prone Eliot Branch near Cloud Cap which closed the trail there in 2007.

Areas of special concern are the Sandy River crossing, where a hiker drowned in 2004,[6] the Eliot Creek, which washed out and closed a section of the trail in 2007,[7] and the Muddy Fork section, which washed out in 2007 and has deteriorated to a point where it is "barely passable" according to a United States Forest Service sign.