The California Trail carried over 250,000 gold-seekers and farmers to the gold fields and rich farmlands of California during the 1840's and 1850's, the greatest mass migration in American history. Today, more than 1,000 miles of trail ruts and traces can still be seen in the vast undeveloped lands between Casper Wyoming and the West Coast, reminders of the sacrifices, struggles, and triumphs of early American travelers and settlers. More than 240 historic sites along the trail will eventually be available for public use and interpretation. The trail passes through the states of Missouri, Kansas, Nebraska, Colorado, Wyoming, Idaho, Utah, Nevada, Oregon, and California.

Have fun exploring science at the Discovery Center of Idaho, located in Boise. Features over 160 hands-on science exhibits, day camps, and a science education resource center.

About 640,000 years ago a massive volcanic eruption spewed an immense volume of ash that covered all of the western U.S., much of the Midwest, northern Mexico and some areas of the eastern Pacific. This was one of many processes that shaped Yellowstone National Park--a region once rumored to be "the place where hell bubbles up." Geothermal wonders, such as Old Faithful, are evidence of one of the world's largest active volcanoes. These spectacular features bemused and befuddled the park's earliest visitors, and helped lead to the creation of the world's first national park.

Craters of the Moon National Monument and Preserve contains three major lava fields covering almost half a million acres and a quarter million acres of sagebrush steppe grasslands. The rugged landscape remains remote and largely undeveloped. The Craters of the Moon lava field spreads across 618 square miles and is the largest young basaltic lava field in the lower 48 states. Sixty distinct lava flows form the Craters of the Moon lava field ranging in age from 15,000 to just 2,000 years old. This lava field contains more than 25 volcanic cones including several outstanding examples of spatter cones. The Kings Bowl and Wapi lava fields, both about 2,200 years old, are located on the southern edge of the Snake River Plain. All three lava fields lie along the Great Rift, displaying some of the best examples of open rift cracks in the world. There are extensive examples of pahoehoe, slabby pahoehoe, shelly pahoehoe, spiny pahoehoe, aa, and block lava, as well as rafted blocks, tree molds, lava tubes, and many other volcanic features. Craters of the Moon is located 18 miles southwest of Arco, Idaho.

Beginning in 1843, City of Rocks was a landmark for emigrants on the California Trail and Salt Lake Alternate Trail and later on freight routes and the Kelton, Utah to Boise, Idaho stage route. The area's historical and geological values, scenery, and opportunities for recreation led to its designation as City of Rocks National Reserve in 1988. The reserve is located 45 miles south of Burley, Idaho.

Hagerman Fossil Beds NM contains the largest concentration of Hagerman Horse fossils in North America. The Monument is internationally significant because it protects the world's richest known fossil deposits from a time period called the late Pliocene epoch, 3.5 million years ago. These plants and animals represent the last glimpse of time that existed before the Ice Age, and the earliest appearances of modern flora and fauna. The fossil beds are located one and one half hour from Boise and thirty minutes from Twin Falls, Idaho.