around the mountain.
Despite the practical difficulties, the idea of walking the entire distance around this towering landmark had great appeal, and it was members of a new organization (what would become the Mountaineers, which started in 1906) who helped to promote the idea with their annual sojourns to the peak. In anticipation of a planned trek by members of the group, several unfinished segments of the around-the-mountain route were hastily completed in the summer of 1914 and early in 1915. So it was in the summer of 1915 that 100 Mountaineers made the first recorded expedition around the peak. It was not until 1921, however, that today’s wonderfully evocative name for the trail was used in a National Park Service (NPS) report. For obvious reasons, the language stuck and the Wonderland Trail was born.
Natural History
Any visitor to a grand natural playground and outdoor laboratory such as Mount Rainier National Park will (or at least should) be interested in learning about the plants, animals, and rocks that surround them. Most people enjoy their visit much more when they can put a name to the things they see and better understand how those elements fit together in an intricate ecological balance. For the hiker, there is no better way to appreciate the enormous natural diversity of the region than by hiking the Wonderland Trail, because that pathway visits almost every major ecosystem in the park, from lowland forests to alpine meadows and rock gardens. This section provides an overview of the fascinating natural history of the park. Interested hikers are strongly encouraged to learn more by talking to rangers, visiting park museums, and reading any of several excellent books about the area’s wildflowers, trees, shrubs, birds, mammals, glaciers, and volcanic eruptions (see Appendix A, for recommended reading).
GEOLOGY
As even a casual glance by the uninitiated quickly indicates, the geologic history of Mount Rainier is dominated by the forces of volcanism and glaciers. Mount Rainier is one of the world’s most massive stratovolcanoes, built up in a series of lava flows and eruptions over thousands of years. All of the dominant rocks in the park are volcanic in origin, including large amounts of andesite and basalt. Early lava deposits that helped to form the mountain are estimated to be more than 840,000 years old, but the present cone is thought to be a little more than 500,000 years old. Countless eruptions, debris flows, landslides, and lahars (volcanic mudflows) have built up and torn down sections of the peak over the millennia, so its shape and profile have constantly changed over time.
Andesite column rock formation below South Puyallup Camp
One of the last really large mudflow events was the Osceola Mudflow, which occurred about 5,600 years ago. During this event a large section of the mountain’s summit collapsed, removing some 1,600 feet from the top of the peak and sending half a cubic mile of debris down the White River Valley. The unstoppable slurry of mud, debris, and glacial ice flowed downstream and covered most of the present-day city of Tacoma. In the process, the flow undoubtedly killed many Native Americans who were, at that time, living around Puget Sound. Since then, there have been countless smaller mud and debris flows, and these continue to occur today. Debris flows have raced down the canyon of Tahoma Creek, for example, as many as two dozen times since the late 1960s. And in 1963 a massive debris avalanche peeled off the slopes of a side peak called Little Tahoma, rocketed down the Emmons Glacier, and nearly wiped out the White River Campground. Fears about a repeat of the Osceola Mudflow, or any of several possible smaller catastrophes, have placed Mount Rainier at the top of the list of the most dangerous volcanoes in the United States. Part of the reason the mountain is so dangerous is that it is covered with such enormous quantities of ice, which could suddenly melt in an eruption and create massive flooding. Another factor that concerns geologists, as well as local disaster-preparedness officials, is the sheer number of people (hundreds of thousands) who now live in areas that could be devastated by an eruption or even by events such as landslides and mudflows that are not necessarily related to eruptive activity.
Though quiet for now, Mount Rainier is still an active volcano. Continuing geothermal heat keeps areas along the summit rim free of ice and has created both a meltwater lake below the ice and an extensive glacial cave network in the mountain’s two summit craters. Reliable eyewitness reports indicate eruptions in 1820, 1846, 1854, 1858, 1879, 1882, and 1894. As of 2012 there is no immediate concern about an eruption, but geologists would not be surprised if the mountain began acting up again.
The second dominant force in shaping the landscape around Mount Rainier is glaciers. These massive, slow-moving rivers of ice gradually carve into, grind up, and carry away huge quantities of rock, leaving behind deep U-shaped valleys, cirque lakes, moraines, and other characteristic features. Today some 25 major glaciers cover approximately 35 square miles of the mountain’s surface, so the influence of these icy monsters is ongoing. In the not-so-distant past, much more of the mountain and surrounding area was under ice. During the most recent glacial period, which ended more than 10,000 years ago, glaciers covered virtually every square inch of what is now Mount Rainier National Park. They even extended down from the mountain all the way to the Puget Sound Basin. Then, during the so-called Little Ice Age, between the 14th century and about 1850, the mountain’s glaciers advanced again, extending, at times, several miles beyond their current locations. Since then, the glaciers have generally been in an uneven state of retreat, with periodic advances, such as in the late 1970s and early 1980s. Today, most of the mountain’s glaciers are thinning and retreating at a relatively rapid rate.
Mount Rainier and snout of Carbon Glacier
A final important factor in carving the landscape around Mount Rainier is the erosive action of the many creeks and rivers that pour off the mountain. These streams inexorably carry away the sand and debris created by glaciers (for proof, look at the heavily silt-laden creeks and rivers you cross along the trail) and slowly carve deep canyons of their own into the tough volcanic rock.
FLORA
Due to the area’s abundant moisture and the park’s dramatic and relatively rapid changes in elevation—from just 1,700 feet at the Carbon River to 14,410 feet at the summit (that’s almost two-and-a-half times the depth of the Grand Canyon)—the vegetation of Mount Rainier National Park is diverse, lush, and beautiful. Well more than 1,100 species of plants—ranging from fungi and lichens to grasses and sedges, numerous species of ferns, hundreds of different wildflowers, several types of shrubs and small trees, and a number of giant coniferous tree species—live here. Because the Wonderland Trail visits all of the park’s vegetation zones, you will have the opportunity during your trip to see virtually all of this incredible diversity of greenery.
Lake James
About 58% of the park is covered by forest. At the lowest elevations, generally below 2,700 feet, are the giant old specimens of western hemlocks, Douglas firs, and western red cedars. Understory trees in this environment must survive in a land of very little light because the canopy above blocks most of the sunlight from reaching the forest floor. Look in these shady areas for Pacific yews, grand firs, and vine maples. The most abundant ground cover species here include devil’s club, thimbleberry, sword and deer ferns, oxalis, and salal. On the few open slopes at these lower elevations, which are kept clear of large trees by frequent avalanches, are dense thickets of alders. Almost 100 species of moss and 200 types of fungi abound in the lush and damp low-elevation environment. Some of the oldest and largest of the trees in this zone are found along the lower reaches of Ipsut Creek and near the banks of the Carbon River, both in the park’s northwest corner and in the Grove of the Patriarchs, just a short side trip off the Eastside alternative to the Wonderland Trail.
As you climb into the midelevation forest zone, which fills the area from 2,700 feet to 4,000–6,000 feet depending on local conditions, you encounter a different mix of conifers. The most notable species here are Pacific silver firs, Alaska yellow cedars, western white pines, and noble firs. The trees here are generally smaller than