Thru-hikers attempt to hike the whole trail in one season. The number of thru-hikes per year has increased steadily. In 2017, 715 northbound and 133 southbound thru-hikes were reported. Many books, documentaries, websites, and fan organizations are dedicated to the hike. Some people hike from one end to the other, then turn around and thru-hike the trail the other way. This is known as a "yo-yo".