While the National Park System protects wide swathes of officially designated wilderness, there are many, many wilderness-quality acres in the parks that are not so designated, though they are managed as de facto wilderness. For instance, while roughly 95 percent of Yosemite National Park is officially designated wilderness, did you know that there is no officially designated wilderness in Yellowstone National Park. And yet, if you headed off into Yellowstone's backcountry you would certainly feel as if you were surrounded by wilderness.

So rich are these natural resources, whether they're officially designated as wilderness or simply managed as such, that President Obama, with hopes Americans will become more familiar with wildneress, has designated September as National Wilderness Month.

What's the big deal? Here's some background:

According to the National Park Service, Congress has designated more than 106 million acres of federal public lands as wilderness: 44 million of these acres lie within 47 parks and total 53 percent of National Park System lands. Additional national park areas are managed as “recommended” or "proposed" wilderness until Congress acts on their status. While it's certainly nice to know that Yellowstone's backcountry is viewed as officially designated wilderness by park managers, without that official designation those acres, believe it or not, some day could be cut by roads or used in some other consumptive ways.

Here's how the Park Service explains the difference between officially designated wilderness and other federal lands that don't carry that designation:

Designated wilderness is the highest level of conservation protection for federal lands. Only Congress may designate wilderness or change the status of wilderness areas. Wilderness areas are designated within existing federal public land. Congress has directed four federal land management agencies—U.S. Forest Service, Bureau of Land Management, U.S. Fish and Wildlife Service, and National Park Service—to manage wilderness areas so as to preserve and, where possible, to restore their wilderness character.

The Wilderness Act prohibits permanent roads and commercial enterprises, except commercial services that may provide for recreational or other purposes of the Wilderness Act. Wilderness areas generally do not allow motorized equipment, motor vehicles, mechanical transport, temporary roads, permanent structures or installations (with exceptions in Alaska). Wilderness areas are to be primarily affected by the forces of nature, though the Wilderness Act does acknowledge the need to provide for human health and safety, protect private property, control insect infestations, and fight fires within the area. Wilderness areas are managed under the direction of the Wilderness Act, subsequent legislation (such as the Alaska National Interest Lands Conservation Act), and agency policy.

The wild, undeveloped areas of national parks (often called "backcountry") are subject to development, road building, and off-road mechanized vehicular use. National park backcountry is protected only by administrative regulations that agency officials can change. The Wilderness Act protects designated wilderness areas by law "for the permanent good of the whole people." With the Wilderness Act, Congress secures "for the American people of present and future generations the benefits of an enduring resource of wilderness."

With that brief primer, here's the proclamation the president issued on Thursday:

The American wilderness has inspired wonder and imagination for centuries and is an irreplaceable part of our Nation's heritage. Even before the birth of the United States, visitors from near and far were struck by its splendor and purity. The unaltered American landscape stood apart from any other in the world. During the years of westward expansion, the wilderness frontier became synonymous with pioneer values of steadfastness and rugged independence. This month, we celebrate this history and renew our commitment to preserving the American wilderness for future generations.

Forty-five years ago, the United States achieved a landmark success in protecting these magnificent wild spaces. The Congress passed and President Lyndon B. Johnson signed the Wilderness Act, which sought to secure "for the American people of present and future generations the benefits of an enduring resource of wilderness." The Act has been widely recognized as one of our Nation's most important conservation laws. This law and the National Wilderness Preservation System it established have served as a model for wilderness protection laws in many of our States and in countries around the world.

The vision and structure established in the Wilderness Act continue to receive broad support. This pioneering law created a framework for bringing Federal public lands under additional protection. Over the past 45 years, the Congress has enacted numerous laws extending wilderness protection to vast swaths of public lands. These laws have enjoyed bipartisan support. Ranchers and anglers, small-business owners and conservationists, and Americans of diverse backgrounds have come together to preserve many of our Nation's most cherished public spaces.

My Administration has already demonstrated a commitment to protecting our wilderness heritage. On March 30, 2009, I signed the Omnibus Public Land Management Act of 2009, which established the most recent additions to our Wilderness System. As my Administration continues to prioritize wilderness protection, we will work closely with the Congress, organizations, and private citizens to ensure that all stakeholders can make their voices heard. United by a common purpose of preserving our precious natural spaces and our wilderness heritage, we will ensure that future generations inherit the unique gift of knowing nature's peace.

NOW, THEREFORE, I, BARACK OBAMA, President of the United States of America, by virtue of the authority vested in me by the Constitution and the laws of the United States, do hereby proclaim September 2009 as National Wilderness Month. I call upon all Americans to visit and enjoy our wilderness areas, learn more about our wilderness heritage, and explore what can be done to protect and preserve these precious national treasures.

IN WITNESS WHEREOF, I have hereunto set my hand this third day of September, in the year of our Lord two thousand nine, and of the Independence of the United States of America the two hundred and thirty-fourth.

Attached below is a list of wilderness proposals pending for National Park System lands, and here's a link to a site where you can explore wilderness across the country.