Created by President Clinton on Sept. 18, 1996, the monument includes 1.9 million acres.
Coal, petroleum and other minerals there have an estimated value of between $223 billion and $330 billion.
881,327 acres — nearly half the monument — are in wilderness study areas.
Grand Staircase-Escalante now has four visitor centers, in Escalante, Kanab, Cannonville and Big Water.
Although use of the visitor centers is rising, overall visitation is trending down, from 696,000 people in 2003 to 613,000 last year.
One study estimates that visitors to the monument spend about $88 million a year in southern Utah.
More than 200 major scientific studies have taken place in Grand Staircase in the past 10 years, recording, for example, more than 300 different kinds of extinct dinosaurs and 648 species of modern bees.
SOURCE: Bureau of Land Management, Utah Geological Survey, Institute for Outdoor Recreation and Tourism, Deseret Morning News archives