# Is there a standard hiking trail difficulty rating system in the United States?

At a local park I've seen hiking/mountain biking trails marked with a green circle, blue square, or black diamond representing easy, intermediate, and hard trails. I've only ever seen this while hiking in this location and wonder if it is displayed for the mountain biking rather than hikers, although the system seems to hold true when hiking.

I came across this nationalparks.fi site which has a similar system for hiking trails with a blue circle for easy, pink square for intermediate, and black triangle for demanding with a short explanation of elevation gain and terrain type for each.

Is there a similar system used in the United States for rating the difficulty of hiking trails?

In short no for hiking trails, the closest one will ever get to a standard difficulty rating are the first 3 classes of the Yosemite Decimal System.

Beyond that, there are many different scales of measuring difficulty,

• Shenandoah's Hiking Difficulty is determined by a numerical rating using the following formula:

Elevation Gain x 2 x distance (in miles). The product's square root is the numerical rating.

How to Determine Hiking Difficulty

• Our trails difficulty ratings are generally based on trail condition, steepness of grades, gain and loss of elevation, and the amount and kinds of natural barriers that must be traversed.

These ratings mean different things depending on if the trail was designed for foot use, for horse use, for bike use or for wheelchair use.

Willamette National Forest

• 1976 he proposed a theory to help backpackers plan trips and calculate their energy needs while on the trail in his book, Teton Trails. His theory states that one energy mile is equal to the energy required to walk one mile on flat terrain. He also said that you need to add two energy miles for every 1000 feet of elevation gain. In other words, if you hiked one mile while climbing 1000 feet, you would've used the equivalent of three energy miles.

Explanation of Hike Difficulty Rating

• American Volkssport Association

• Outdoors.org

• Hike difficulty calculator

Some of this has to do with subjectivity behind the ratings and part of it with how different the trails can be. For that matter hiking the same trail in the opposite direction can be way different.

• I wonder why they use the square root of "Elevation Gain x 2 x distance." In my experience, 4000ft of gain over two miles is much harder than 4000ft of gain over four miles. Commented Sep 8, 2018 at 2:30
• There are magic numbers: Somewhere between 6% and 8% grades, you have to put your foot down with bent knee. Perceived effort goes way up. Somewhere between 12% and 20% your heels stop hitting the ground. Like stairs. Travel rate is now determined by vertical distance. Perceived effort increases again. Commented Sep 10, 2018 at 14:54