"World Ranger Day," one day out of the year to show your appreciation for national park rangers the world over, arrives this week.

The staff of Rocky Mountain National Park invites you to celebrate the day as they recognize world conservation areas, and the professional staff -- the rangers -- who form the Thin Green Line around these most valuable resources.

On Tuesday, park staff will show The Thin Green Line, an international ranger documentary made by Australian Ranger Sean Willmore. The program will begin at 7:30 p.m. at the Beaver Meadows Visitor Center auditorium in Rocky Mountain National Park.

The International Ranger Federation (IRF) was founded to support the work of rangers as the key protectors of the world's protected areas. In 2006, at the World Ranger Congress in Scotland, IRF delegates decided that July 31 of each year, beginning in 2007, would be a day dedicated to world rangers. The first World Ranger Day fell on the 15th anniversary of the founding of IRF on July 31, 1992.

Rocky Mountain National Park is celebrating a day early.

In 1872, Yellowstone National Park became the world's first federally designated national park. Since then, according to the International Union for the Conservation of Nature, over 100,000 protected areas, representing more than 10 percent of the earth's landmass, have been established around the world.

The English word "ranger" reflects the guardians of the Royal Forests in 14th century England, protecting the king's lands from poachers. Today, rangers in protected areas throughout the world continue this role for the public, not just for the royal families.

Rangers are the key force protecting these resources from impairment. They do this through law enforcement, environmental education, community relations, fighting fires, conducting search and rescues, and in many other ways.

Come show your support for the Rangers of the World at this free program Tuesday, July 30, 7:30 p.m. at Beaver Meadows Visitor Center.