Glacier National Park officials, frustrated by six days of fruitless searching for a missing hiker, say they'll scale back efforts on Tuesday unless new leads are discovered.

Backcountry rangers in some Alaska national parks routinely signal their position with "Spot," a personal locater beacon that can be used to summon help or to simply let friends know you're OK. Recently, Spot helped rangers find two backcountry travelers in Sequoia National Park who found themselves in trouble.

Once the national cemeteries were established, they were effectively the only areas of the battlefields in a condition adequate to receive the public in any numbers, and they became the focal points for official ceremonies and other formal acts of remembrance. Most widely observed was Decoration Day, begun at about the end of the war in response to the massive loss of life suffered during the four-year conflict.

A little more than century after President Theodore Roosevelt designated Natural Bridges National Monument, making it the first National Park System unit in Utah, the monument will serve as the backdrop for a celebration of 100 years of national parks in the state.