Easy Terrain
Little-to-no daily elevation gain. Average elevation is not high enough to necessitate acclimatization. Temperature and weather conditions are mild in the hiking season. Trail is extremely well marked, well-maintained, and easy to follow.
Moderate Terrain
Trail elevation changes gradually through the course of the day, or some days include sustained climbs and descents. Average elevation might necessitate acclimatization in some cases. Temperature might dip below 32 F nightly or above 75 F daily. Weather is mostly pleasant with occasional challenges. Trail is well-marked and well-maintained, but might include instances of sign-reading, route-finding, or other navigational skills.
Difficult Terrain
Elevation changes drastically on a daily basis. Most days include sustained climbs and descents. Average elevation might necessitate acclimatization, with instances of climbs above 12,000 feet possible. Temperatures almost certainly drop below 32 F nightly or rise above 75 F daily. Weather conditions could be hazardous even in prime hiking season, with storms, high heat, or extreme cold possible. Trail could be poorly maintained or marked in sections, and navigational skills and tools are recommended.
