The Pacific Crest Trail is in the USA. It starts on the border with Mexico. It ends on the border with Canada. It is 2,600 miles long (4,184 kilometres). It goes through the mountains of California, Oregon and Washington.
A man goes on the trail. He takes a selfie at every mile (1.6 kilometres). He turns the pictures into a video. You can see how he changes. He is a little fat at the beginning of the video. At the end, he is not. He lost 50 pounds (23 kilograms).
The man did not finish the trail. He stopped 418 kilometres from the end – there was a snow storm.
Difficult words: crest (the top of a mountain or a hill), trail (a way in the countryside), border (an area where two countries meet).