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.

This 76-mile reach of the Niobrara River in northcentral Nebraska was added to the nation's Wild and Scenic River System in 1991. The river is swift and shallow over much of its length, cutting through bedrock forming riffles, rapids and waterfalls. The Scenic River preserves a superb example of a Great Plains river and protects a unique ecological crossroads where six distinct ecosystems and their associated flora and fauna mix, some at or beyond their normal geographic limit. The western third of the Scenic River is home to over ninety waterfalls -- highest is Smith Falls that cascades seventy feet from a Sand Hills cliff. Many locally-owned ranches are found along the river retaining the valley's rural flavor, yet much of its wild character is preserved. Wildlife abounds: animals such as white-tailed deer, coyote, beaver, mink, bull snakes, soft-shelled turtles, turkeys, herons, and sandpipers are commonly sighted. Enjoyed by tens of thousands of canoeists yearly, the upper reach of the Niobrara is noted as one of the country's outstanding canoeing rivers. A portion flows through a federally designated wilderness.

Agate Fossil Beds near Harrison is an internationally recognized fossil site. The landscape surrounding the fossil beds has been a site of change for millions of years. Agate has also been a home to people like James and Kate Cook; leaders of great nations like Red Cloud and American Horse. The weathering of sedimentary rock, bones becoming visible in cliffs, and the gifts presented to James Cook by the Lakota Sioux are all reflective of the strong natural and cultural relationships of the Agate landscape. The Monument preserves bones in one of the best preserved Miocene mammal sites in the world.