Yellowstone has many opportunities for hikers of all levels. Trails are normally classified by length and difficulty to help you decide which hikes are suitable for your trip. Day hikes are normally 1 to 10 miles long and can vary from leisurely, flat hikes to quick pushes up a ridge or peak. Backcountry trails are longer and vary considerably, often with more than one terrain type on the same trail. It is important to look at a topographic map of a trail route before hiking it.
Yellowstone can be divided into sections based on the points of the compass. To the north lies Mammoth Hot Springs, the Gallatin mountain range and the Grand Canyon of the Yellowstone. The east and southeast contain Yellowstone Lake and the Absoroka Mountains. The west and southwest are generally referred to as West Yellowstone and contain most of the park's geothermic geyser basins.
Trails in the north of Yellowstone include day hikes of all levels around Mammoth Hot Springs and backcountry trails in the Gallatin range. Most of these trails are moderate or easy and are centered around the hot springs, though some move through the mountains and forests surrounding the area.
The geyser basins in West Yellowstone are the center for hiking in this region and feature a large number of day hikes. The backcountry is also very accessible from this point, with a large network of trails running into the southwest. Large plateaus in this area keep the trails at a moderate level with fairly low elevation changes.
To the east lie day trails around Yellowstone Lake and up into the Grand Canyon of the Yellowstone. Backcountry travel is plentiful and can be rugged in the mountains in the northeast. The trail network dies off to the southeast.
The roads running into the heart of the park are closed during the winter months, so access to trails is limited. Some day trails are open for cross-country skiing during the winter, but from November through late March, the normal trail network is covered by snow.
Day hikes and backcountry trails often intersect, so be wary of choosing a trail you are unfamiliar with. Many trails leading into the backcountry join with quite long networks and can turn a short jaunt into an all-day hike. Always carry a trail map on your shorter hikes, and plan your route carefully before making any trail changes.