The Pacific Crest Trail was first proposed by Clinton C. Clarke, as a trail running from Mexico to Canada along the crest of the mountains in California, Oregon, and Washington. The original proposal was to link the John Muir Trail, the Tahoe-Yosemite Trail (both in California), the Skyline Trail (in Oregon) and the Cascade Crest Trail (in Washington).
The Pacific Crest Trail System Conference was formed by Clarke to both plan the trail and to lobby the federal government to protect the trail. The conference was founded by Clarke, the Boy Scouts, the YMCA, and Ansel Adams (amongst others). From 1935 through 1938, YMCA groups explored the 2000 miles of potential trail and planned a route, which has been closely followed by the modern PCT route.
In 1968, President Lyndon Johnson defined the PCT and the Appalachian Trail with the National Trails System Act. The PCT was then constructed through cooperation between the federal government and volunteers organized by the Pacific Crest Trail Association. In 1993, the PCT was officially declared finished.
 Thru Hiking
Thru hiking is a term used in referring to hikers who complete long distance trails from end-to-end in a single trip. The Pacific Crest Trail, Appalachian Trail, and Continental Divide Trail are the three long distance trails in the U.S. Successfully thru-hiking all of these three trails is known as the “Triple Crown of hiking.  Thru-hiking is a long commitment, usually taking between four and six months, that requires thorough preparation and dedication. Although the actual number is difficult to calculate, it is estimated that around 180 out of approximately 300 people who attempt a thru-hike complete the entire trail each year. 
The first thing prospective thru hikers have to do when thinking about attempting a thru hike is planning their trip. The Pacific Crest Trail Association estimates that it takes most hikers between 6 and 8 months to plan their trip.  The first decision during the trip planning process is to decide the route to take. Most hikers travel from the Southern Terminus at the Mexico Border north to Manning Park, British Columbia, but some hikers travel southbound. In a normal weather year, northbound hikes are most practical. If snowpack in the Sierra Nevada is high in early June and low in the Northern Cascades, some hikers may choose to 'flip-flop.' Flip-flopping can take many forms but is often the term used to describe beginning at one end (on the PCT, usually the southern end) of the trail and then, at some point, like reaching the Sierra, going to the end of the trail (Manning Park in B.C.) and hiking southbound to finish the trail.
Hikers also have to determine their resupply points. Resupply points are towns or post offices where hikers replenish food and other supplies such as cooking fuel. Hikers can ship packages to themselves at the U.S. Post Offices along the trail, resupply at general and grocery stores along the trail, or any combination of the two.  The final major logistical step is to create an approximate schedule for completion. Thru hikers have to make sure they complete enough miles every day so they will be able to reach the opposite end of the trail before weather conditions make sections impassible. However, the snow pack in the Sierra Nevada can prevent an early start. The timing is a balance of not getting to the Sierra too soon nor the Northern Cascades too late. Most hikers cover about 20 miles (32 km) per day.
In order to reduce their hiking time to increase their chances of completion many hikers try to substantially reduce their pack weight. Since the creation of the Pacific Crest Trail there has been a large movement by hikers away from large heavy packs with a lot of gear. There are three classifications for hikers: Traditional, Lightweight, and Ultralight.  Very few hikers are traditional hikers anymore. The Pacific Crest Trail Association cites Ray Jardine’s book Beyond Backpacking as a great resource for hikers during the planning process.  Beyond Backpacking is a “how-to” book for ultralight hikers. In this book Jardine explains how to trim every extra ounce from one’s pack weight by doing everything from cutting extra straps off your pack to eating only food that does not have to be cooked. 
 Notable Hikers