Most visitors to Yellowstone National Park see just the tip of an immense, complicated iceberg.

When you drive through the park's 2.2 million acres, you can see a great deal: bears, wolves, elk, bison, geysers, mountains and forests. What the visitor doesn't see from the road is about 98 percent of the park, a backcountry region that's managed as wilderness and patrolled by 22 elite rangers on horseback, skis and on foot.

For the better part of a century, they have served the public as field guides, informal educators, medics, rescuers and law enforcement officers. They also have forecountry responsibilities, such as trying to prevent 600 vehicular accidents annually or the loss of 100 animals struck by vehicles.

In recognition of those responsibilities and that heritage, the Yellowstone Park Foundation has launched a Ranger Fund initiative, to raise $2 million in two years.

For years, the foundation has raised money for one project at a time, said Executive Director Paul Zambernardi. About the time he came on board last May, the foundation's board adopted a thematic fundraising strategy - the first of which was the Ranger Fund initiative.

The Ranger Fund started with the realization that the livestock facility at Steven's Creek needed to be redeveloped, said Zambernardi, including a much-needed barn for rider and stock training, storage space to house saddles and tack, and space for veterinary supplies for the more than 100 head of horses and mules used to patrol the backcountry.

"The backcountry cabins are also showing signs of wear and tear," said Zambernardi, "and they can be made more comfortable."

The Ranger Fund would provide the Yellowstone rangers with the equipment, supplies and support they need to efficiently protect people and resources in the park's vast backcountry, the foundation says.

Zambernardi said the initiative would fund new signs on roads to slow visitors down, and provide patrol gear and GPS equipment for search and rescue efforts.

"We also want to upgrade the ranger museum at Norris to make it more interactive and more of a destination attraction," he said.

The Ranger Fund seeks proper restoration and curation of exhibits at the Museum of the National Park Ranger in order to educate visitors about the evolution of the ranger's role in Yellowstone and its rich cultural history throughout the National Park Service.

Zambernardi said the foundation has already raised $430,000 toward the $2 million goal of the Ranger Fund. He and his staff are also working to raise $500,000 for the Archive Fund, $500,000 for the Fisheries Fund and $2 million for the Trails Fund.