Vintage postcards of U.S. National Parks
The National Park Service is inviting people to take part in the celebration of its 100th anniversary on Thursday. Since 1916, the federal agency has been entrusted with the conservation of the United States' national parks, national monuments and other protected areas. More than 275 million people visit these breathtaking preserved places every year. (Read more by Michael Walsh/Yahoo News) Here’s a look at a few vintage postcards of some of our national parks.