Redwood National and State Parks, California: Want to see the world's tallest tree? You could get fined $5,000

The tree recognised as the tallest in the world is now off-limits to visitors.

The National Park Service announced last week that it is discouraging hikers from visiting Hyperion, an old-growth redwood in Northern California that holds a Guinness World Record for height at 380 feet, 9.7 inches (116.07m), according to a 2019 measurement. People who are caught in the closed area of Redwood National and State Parks could face a $US5,000 ($A7,123) fine and six months in jail, NPS says.

The tree, which was "discovered" in 2006, is located off designated trails and amid dense vegetation that requires heavy bushwhacking.

"Despite the difficult journey, increased popularity due to bloggers, travel writers, and websites of this off-trail tree has resulted in the devastation of the habitat surrounding Hyperion," a National Park Service bulletin says.

According to the park service, the number of people trampling through the area over the years has caused the base of the tree to degrade and has wiped out ferns that would normally surround it. Trash and human waste have also been found littered on the way to the world's tallest tree.

In addition to the damage and litter, getting to Hyperion can be dangerous because hikers have to go completely off the trail to access it. The tree is rooted in an area that doesn't have cellphone reception and has spotty GPS coverage, according to NPS, so suffering a small injury could be scary and dangerous.

In its release, the park service discourages people from visiting Hyperion by pointing out that it's not as exciting as it sounds.

"A view of Hyperion doesn't match its hype," the NPS statement says, adding that the tree's trunk is small in comparison with many other old-growth redwood trees and its height can't be observed from the ground.

The "tallest tree" label is a moving target of sorts. Years ago, the park created a Tall Trees Trail so hikers could see a tree then designated as the world's tallest tree. That tree no longer holds the title, but the trail features many redwood trees that exceed 350 feet, NPS says.