Two trees fell in a forest and, while no one was there to hear them fall, news of their collapse echoed across the country.
"You notice when a sequoia falls," said Al Nash, a park service spokesman in Washington, D.C. "These magnificent trees are so overwhelming, everyone notices when one falls."
Not only did the crashing of the two 200-foot high giant sequoia trees in late February make news, the incident has also cast attention on a dilemma facing park officials throughout the country: Is it possible to love parks too much?
The National Parks Service estimates that nearly 280 million people visit national parks each year for recreation. At Yosemite National Park, where the two sequoias toppled, between 3 million and 4 million people enter the park every year.
It's not yet clear what caused the two towering trees to tip — in fact, their toppling may have been completely natural. But officials said that human foot traffic could have been a factor.
Too much trampling around the trees' root systems can pack down the soil and block the flow of oxygen and water to the trees' roots. Some are also concerned that smog from car traffic inside the park degrades foliage of the trees and other vegetation.
To protect the park's remaining sequoias, other terrain and wildlife, some have proposed limiting both automobile and foot access to the park.
Keeping Cars Out
A controversial plan, devised during the Clinton administration, would reduce day-use parking by two-thirds, add shuttle bus service to replace car traffic, create more protections around trees' root systems and close some riverside camp sites. The proposal by the U.S. Environmental Protection Agency, is expected to be finalized next year after public comment.
"We need to make sure that visitors feel welcome, but at the same time we must make sure our resources are protected," said National Park Service Director Fran Mainella at a hearing about the plan in Yosemite National Park on Tuesday.
Yosemite National Park is one of a growing number of national parks across the country where officials have adopted or are looking to adopt new rules to restrict auto and some foot access to sensitive regions.
Snowmobile access to Yellowstone National Park has been curtailed, cars have been replaced by shuttle busses in the interior of Utah's Zion National Park and Montana's Glacier National Park in Montana. Even smaller parks, like Great Falls Park in Virginia, are adding traffic restrictions inside their gates.
"We're always trying to find the balance between accommodating visitors and protecting the resources," said Nash.
At Zion National Park and Glacier National Park, more frequent sightings of rare wildlife, including mountain lions, have suggested the new rules have made a difference.
Too Much Attention?
For the giant sequoias in Yosemite, reduced tampering could add hundreds of years to their life spans, say researchers. Giant sequoia trees can grow taller than the Statue of Liberty and can live for more than 3,000 years.
"As more of these trees become increasingly recognized because of their grandeur, more attention has to be applied to protect them," said Steve Sillet, a botany professor at Humboldt State University in Northern California, who specializes in coastal redwoods and giant sequoias. "Footsteps over time have a massive pounding effect to the trees' root systems."