Overview
The Pacific Crest Trail follows the Sierra Nevada and Cascade mountain ranges. It reaches across the United States from the Canadian border to the Mexican border, and passes through 7 national parks along the way. It is very famous, and has been portrayed in many popular movies. The trail is considered to be moderate/strenuous. Much of the difficulty lies in the extreme length of the trail, which is difficult to complete even for experienced hikers. However, the terrain grading and conditions are often more mild than in trails of similar comparison, like the Appalachian Trail on the opposite side of the country, but this will depend heavily on the section.
Terrain
The PCT travels through many varied types of terrain. The trail starts out in the Mojave desert, which then fades into the Sierra Mountain Range, which even includes alpine regions. Due to these variations, hikers will often switch out gear depending on the trail section. For example, if there is still snow in the higher elevations, hikers may need more specialized gear, which they can then shed upon reaching lower elevations.
Water
Natural water sources are typically reliable, but the amount of water available will depend on the climate of that year. There is a crowdsourced table of water information online that can be useful for preparation. Additionally, maps and guidebooks usually have general data on where to access clean water. Hikers will need some type of water filtration system to clean the water before use.
Resupply
Despite going through vast wilderness areas, the route passes through many small towns where hikers can frequently resupply on food from small local grocery stores. Most hikers take advantage of these for the majority of resupply needs. However, many hikers also choose to use bounce boxes, in which they mail supplies to post offices along the trail where they can pick it up, and then re-mail it ahead. There are some caveats here, including short post office hours, extra time needed in towns, cost, etc. But for certain supplies, they cannot be beat. In that case, guidebooks usually provide some data on mailing information, and there are also online resources for additional research.
Weather
Towards the southern end of the trail, the weather is generally more pleasant, as is typical of the region. However, the areas further north have more sporadic conditions. Snow may be present at higher elevations, which necessitates specialized gear. Other areas like the Cascades may have severe storms without much warning. Additionally, certain drier areas may be closed off due to fire concerns. The Pacific Crest Trail Association maintains a page that has the latest information on all trail conditions and closures which can be very useful both on and off the trail.
Navigation
The majority of the trail is marked at intersections. Additionally, the path itself is popular and well-traveled, which should make general navigation safer. However, there are many areas where the signs and paths cannot be fully relied upon. Some sections will simply not have signposts. Areas that are covered in snow will be very difficult to navigate, and some hikers will resort to using a GPS in those cases. It is often best to carry a combination of maps/guidebook in addition to a GPS in order to cover all scenarios. Local reports online will also contain useful detailed information on how to navigate.
Hazards
As with most trails, the most significant hazard is unpredictable weather and terrain. Snow-covered paths can make navigation near impossible. While severe storms can appear without warning in the mountain ranges. The best safety net is advanced preparation in terms of gear, supplies, and knowledge. Encountering the wildlife is usually of lesser concern, but bear canisters will be required in certain parts of the trail.
Popularity
The PCT is one of the most popular long distance hiking trails in North America, partially due to its portrayal in many popular movies. It will have the most foot traffic during peak season and in the more pleasant hiking regions. The crowds will thin out in more challenging sections, as there will be fewer day hikers and section hikers. The crowds will make certain logistical aspects of the hike simpler, such as navigation and finding information on water access and resupply points along the trail.
Transportation
The southern terminus of the trail is easily accessible by public transportation in San Diego, but the northern terminus is more difficult to access in Manning Park on the Canadian border. The PCTA publishes more detailed transportation info for accessing both parts. In general public transportation along the trail is sporadic, depending on which towns along the way have bus or train services. The Amtrak and Greyhound websites can help in planning out your transit options.
Accommodation
There is some availability for developed accommodation in towns along the way, and guidebooks should have detailed information about facilities in each area. In the remote areas of the trail there are only a few huts and shelters available for hikers. Hikers will need to carry and use their own shelter in the form of a tarp or tent for the majority of the hike.