In 1991, the Dyerville Giant fell to earth.

The tree was a 110-meter (362-foot) coast redwood in Humboldt Redwoods State Park, California, United States. It was taller than the Statue of Liberty. The crash was so loud that people in the closest towns thought it was the noise of a big train accident. The redwood's fall moved the earth. Vibrations registered on a nearby seismograph, a device scientists use to measure earthquakes.

Dave Stockton runs the Humboldt Redwoods Interpretive Association, a group of volunteers that run visitor centers and tours for the park. He remembered visiting the downed redwood the day after it fell. Stockton walked alongside the tree past its base. Its unburied roots stick up from the ground.

The toppled Dyerville Giant is one of the many amazing trees that Stockton showed me while walking around the park in 2010. Redwood trees are the tallest trees in the world. The park is home to some that rise more than 107 meters (350 feet) into the air.

The park's redwood trees are called coast redwoods (Sequoia sempervirens). Their range stretches along the coast of California. The tallest coast redwood is in Redwood National Park, nicknamed the Hyperion Tree. The previous record-holder was the Stratosphere Tree, found in Redwoods State Park.

Rockefeller Forest

One of Humboldt Redwoods State Park's finest features is the Rockefeller Forest. It is a collection of redwoods that were never cut down by the area's logging companies. Stockton and I looked at the giant trees. Their twisted bark makes the redwoods look like giant strands of braided rope.

The Rockefeller Forest is known as one of the finest groves of redwoods in the world. It has trees of all ages. There are "dog hairs," young, thin redwood trees that cover the ground in patches. Older redwoods have what are called goose pens. These are large burnt-out caverns in the base of the trees. Oldest of all are the decaying stumps that stick out from the earth like giant teeth.

Stockton says redwood trees grow and thrive within the park for several reasons. The trees like the area's mild temperatures and coastal fog. (The trees collect moisture from fog.)

Some of the redwood trees in the Rockefeller Forest are covered with spiderwebs. They almost look like beards. It's appropriate since the redwoods here are very old. The average redwoods in Rockefeller Forest are estimated to be 600 to 800 years old. The oldest are up to 2,000 years old. Redwoods are able to reach such ages because they have high amounts of tannin, a compound that keeps insects away. The trees also have low amounts of resin, which helps them survive forest fires.

Threats to Redwoods

Stockton believes the greatest natural danger to redwood trees is high wind. The trees can grow hundreds of feet into the sky. However, they have a shallow root system that grows less than three meters (9.8 feet) into the ground. In a windstorm, the redwoods can really sway.

Humans have long prized the wood of redwood trees. Some local Native American peoples built canoes and sweathouses out of the tree trunks. They used the roots to make baskets. In the 1850s, loggers harvested redwoods for buildings and railroad ties.

The forests are important to many plants and animals. Bats frequently live within redwood trunks that have been hollowed out by fire. The marbled murrelet (Brachyramphus marmoratus), an endangered seabird, builds its nests on the wide branches of redwood trees.

Stockton says that when a redwood falls, the number of species taking up residence on the tree doubles. The fallen tree has more contact with the ground. This allows more animals and plants access to water that is stored within it. Downed redwoods frequently host a large number of insects. They provide dens for animals, including skunks and foxes.

The Rockefeller Loop Trail passes through a section of forest called Cathedral Grove. It featured the most stunning redwoods of the hike. Sunlight slipped down through the redwood branches as Stockton described what he finds most amazing about redwood forests. "It's so quiet," he said.