U.S. Secretary of the Interior Ken Salazar designated six new spots as national natural landmarks in June, 2011.

The secretary, responsible for the management and conservation of most federal land and natural resources, named the new landmarks in four western states that are home to unique natural treasures including hanging gardens, fossil footprints and rare Palouse prairie.

“One of the major goals of President Obama’s America’s Great Outdoors initiative is to develop a conservation ethic for the 21st Century,” Salazar said in a statement.

“By designating these remarkable sites in Arizona, Colorado, Oregon, and Washington as national natural landmarks, we help establish and pass down to future generations those awe-inspiring places that make America truly beautiful.”

The new national natural landmarks are Barfoot Park (Arizona), Golden Fossil Areas (Colorado), Hanging Lake (Colorado), Kahlotus Ridgetop (Washington), Round Top Butte (Medford, Oregon), and The Island (east-central Oregon).

With the latest six additions, America now has 591 national natural landmarks.

Barfoot Park in the Chiricahua Mountains of southern Arizona supports an unusual mix of Sierra Madre and Rocky Mountain flora and fauna that includes four pine species and 18 other tree species. It also includes more than 15 acres of talus slopes, along with three meadows and two permanent springs. The landmark encompasses 680 acres of federal land managed by the U.S. Forest Service.

The 19-acre Golden Fossil Areas west and north of Golden, Colo., were designated as an extension to the existing Morrison Fossil Area National Natural Landmark, which will now be known as the Morrison-Golden Fossil Areas National Natural Landmark. The Golden Fossil Areas are among the most important paleontological sites in the Front Range and the western United States. They are known internationally as the only sites in the world to have produced a number of unique fossil footprints representing reptiles, birds, and mammals.

Hanging Lake National Natural Landmark is located along I-70, east of Glenwood Springs, Colo. The site is an outstanding example of a lake formed by travertine deposition. The lake and associated falls support a rare wetland ecosystem, including hanging gardens. The 72-acre site is situated within the White River National Forest.

Kahlotus Ridgetop National Natural Landmark is a remnant of the Palouse Prairie located about four miles north of Kahlotus, Wash. The Palouse Prairie is the most endangered and the most altered landscape in the inland Pacific Northwest. Approximately 1 percent of the original prairie remains and occurs in small fragments in developed landscapes. This 240-acre site is managed by the Washington Department of Natural Resources.

Round Top Butte National Natural Landmark includes a basaltic butte, flat volcanic plains and small hills near Medford, Ore. Its vegetation is a mix of dry grassland, ponderosa pine, white oak and buck brush. The habitats are exceptional because they are dominated by native bunchgrasses. The new landmark encompasses 747 acres in two parcels: an established Research Natural Area managed by the Bureau of Land Management, and a preserve managed by the Nature Conservancy.

The Island National Natural Landmark is located on an isolated plateau at the confluence of the Deschutes and Crooked rivers in east-central Oregon. This 208-acre site supports one of the best known and least disturbed examples of native juniper savanna located within the Columbia Plateau. The Island is also a designated Research Natural Area, and is jointly managed by the Bureau of Land Management and the U.S. Forest Service.