Many visitors, noting the low, rolling hills and general inaccessibility of the Yukon-Charley area, wonder what qualities make it unique in America. The National Park system, after all, encompasses a variety of natural, cultural and historical sites and each one, in its own way, is nationally significant. So just what does make Yukon-Charley Rivers important to our national heritage? In addition to preserving a segment of the Yukon River, one of America’s mightiest and most storied wild rivers, the preserve was established to protect some key values.
As early as 1898, surveyors were noticing the presence of Peregrine Falcons in the area. When pesticide use threatened the existence of the Peregrines, it was already well known that Yukon-Charley Rivers was critical habitat for their recovery. For that reason, and for other raptors and wildlife in the area, congress created the National Preserve to assist in their recovery. Alaska is home to a large percentage of the nation’s Peregrines and Yukon-Charley Rivers is host to 20% of that population. In recent years, the population of Peregrines has soared, and their recovery so successful that they have since been removed from the endangered species list. Why is Yukon-Charley such good habitat for the Peregrines? Why do we have such a high percentage of Peregrines here in Yukon-Charley? The area is wild and undeveloped and the birds are minimally stressed by humans. They also have large waterways to hunt along and steep bluffs rising from the river offer excellent locations for hatching and raising their young. Peregrines hunt birds in Yukon-Charley during the summer and migrate over 5,000 miles to Central and South America for the winter. Both the male, which is two-thirds the size of the female’s size, and the female hunt to feed the young. If you are lucky, you may see a Peregrine hunt other birds on the wing at speeds up to 200mph (320 Kilometers). Or perhaps, if you are quiet near a bluff, you will see a high-speed food exchange between the male and female in midair.
Anyone who passes by Calico Bluff looking for Peregrine Falcons, cannot help noticing the charcoal and cream colored, folded and warped layers of the bluff itself. While a thin skin of vegetation and soil covers much of the Yukon-Charley’s geologic strata, the rocks that lie below have quite a story to tell. Geologist Dr. Carol Allison noted: In terms of occurrence in a relatively small area, completeness of a depositional record, and persistent presence of fossils, this area is unique in America; in fact, a search for a comparable record elsewhere, based on these criteria, failed to locate a single candidate in the world. Yukon-Charley’s rich history is filled with warm, shallow seas, volcanic activities and continental collisions. The unusual and remarkable depositional history continues to baffle geologists. The rocks north of the Yukon and overlying the Tintina fault record in almost unbroken succession, the history of the area from about 800 million years ago, to the Cenozoic Era, about 40 million years ago; an unparalleled 760 million years. Yet another aspect of the geology in these parts is interesting. You may have noticed that gold discoveries in this area are exclusively on the south side of the Yukon. Why? The Tintina Fault stretches east-west through Yukon-Charley Rivers. It is best known for its role in the Klondike Gold Rush. Millions of years ago two crustal plates shifted along the Tintina Fault and caused superheated water to carry readily soluble minerals, including gold and silica, toward the surface. As the water cooled in myriad cracks formed in the fault zone, silica precipitated out to form quartz. Impurities such as gold trapped in the quartz concentrated as well. Pockets of gold existed in the rock around the fault zone until erosive forces tore the gold from the gold from the quartz’s grip and sent it tumbling down mountain streams. As the gold churned with other rock, it gradually settled to the bottom. Placer mining, since the Klondike gold boom, has been a method of removing gold from the gravel to which it is mixed. (For more information on the geology of the Preserve, see the pdf document Geology Down the Yukon.)
More recently in geologic history, one of Earth’s most dramatic surface forces, glaciation, left this area virtually untouched for the last 20,000 years. The vast glacial systems that covered most of Alaska, most of Canada and northern sections of the continental United States skipped this interior region. As the glaciers grew, ocean water lowered, exposing the Bering Land Bridge. Somewhere between 10,000 and 25,000 years ago, or even several times during that period, people traveled across the exposed lands and unwittingly discovered the "New World." Yukon-Charley Rivers may have been one of the earliest homes for humans in the Americas since glaciers did not scour the Yukon corridor after humans crossed and because the Yukon River would have been such a natural corridor for their travel. Reconnaissance surveys have revealed three prehistoric occupations of the area beginning about 11,000 years before present and continuing almost until the Klondike time period. A comprehensive survey has yet to be completed, but if remains are found older than 10 to 12 thousand years old, the Bering Land bridge theory of the peopling of Alaska and the Americas will be stronger.
Moving further in history, the discovery of gold and the ensuing Klondike Gold Rush changed the land forever. Many rugged people who came to this edge of Alaska stayed on, living with the land and extending America’s frontier days well into this century. Yukon-Charley’s dynamic history includes dog teams and road houses, winter mail routes, arctic explorers, riverboats, and a richly textured native history. The Yukon River was most populated in the first thirty years of the past century. When major gold strikes drew people to other lands and fur prices dropped in the thirties, many people left the country. World War II essentially spelled the end of the organized culture in the preserve. Because development along the river decreased we have the fortune of preserving many cultural sites along the river that did not disappear under the bulldozer of development.The Athabaskans who survived in this region for over the last thousand years, the gold prospectors and people who followed them, and even the people today who live with the land are testament to people’s ability to adapt and survive.
