Trail difficulty rating systems provide a shorthand way of knowing how long a trail is, how much elevation it gains, and its overall hiking difficulty. These systems help hikers choose the right trails for their skill levels and ensure a safer and more enjoyable experience.

While there are many trail rating systems worldwide, the one most used in the U.S. is the Yosemite Decimal System (YDS). Understanding the rating system for hiking trails is essential before you set off to try a new route.

The Yosemite Decimal System: A Quick Overview 

Originally developed in the 1950s by the Sierra Club, the Yosemite Decimal System (YDS) has become the go-to rating system for hiking and climbing routes in the U.S. It’s designed to classify trail difficulty ranging from simple, well-maintained trails to technical climbs needing specialized climbing skills and equipment.

The 5 Rating Levels of the YDS 

Familiarizing yourself with the five levels of the YDS and what they mean will help you choose trails best suited to your experience and abilities:

Class 1 (YDS 1): Easy walking on well-maintained, marked trails with minimal elevation gain and no hands needed for balance. Suitable for all skill levels and ages. 

Class 2 (YDS 2): Slightly more challenging, with steeper terrain and the occasional use of hands for balance. Some areas may involve off-trail hiking, and the trail markings may not be clear. Still suitable for most hikers with basic experience. 

Class 3 (YDS 3): Moderate scrambling that may require the use of hands for climbing short sections. Some exposure to height and potential falls. This rating recommends the use of hiking boots and having hiking experience. 

Class 4 (YDS 4): More difficult scrambling, with increased exposure to heights and potential falls. Hikers might need ropes and basic climbing gear for safety, and prior climbing experience is necessary. 

Class 5 (YDS 5): Technical rock climbing requiring ropes, harnesses, and other specialized climbing gear. Experience, skills, and knowledge of climbing techniques and gear usage are essential.

Trail Rating Tips and Cautions for Novice Hikers 

Before choosing a trail, check the YDS rating, distance, elevation gain, seasonality, and any possible hazards. The local trail guidebook should include these descriptions. Be realistic and stay within your capabilities. Remember, you’re out there to enjoy yourself and experience natural beauty; don’t turn it into a contest and try to prove yourself against a challenge that may be too much for you.

Monitor the weather forecast. Rapid weather changes can be dangerous, especially in the mountains.

It’s not just the rain and snow that can catch you off guard in the Sierra: heat is an increasing danger. Even experienced hikers pay special attention to common sense precautions for hiking in hot weather .  

Bring all the recommended supplies, like food and water or sports drinks, a fully charged phone and GPS, a first aid kit, sunscreen, a warm and waterproof jacket in case of a quick change in the weather, a flashlight or headlamp, and a whistle to signal rescuers if something goes wrong.

With a solid understanding of the rating system for hiking trails, plus common-sense supplies and precautions, you’ll be ready to embark on your next hiking adventure in the Sierra.