Christopher Paik has been climbing the steep rock face of Mather Gorge at Great Falls Park for 10 years. Like many other rock climbers, he believed injury was just about the only thing that could keep him from the sport.

But that was before the National Park Service announced a plan that could restrict climbing in the park to preserve the landscape and restore such rare plant species as the Nantucket shadbush and flattened spikerush.

Now Paik and other climbers say the use of the popular cliffs and ledges that attract hundreds of rock climbers to the Virginia side of the river each week is in jeopardy.

"They want to reduce the impact [on the land], and the way to do that is by restricting climbing," said Paik, 44, a lawyer for the Securities and Exchange Commission. "But the view [of climbers] is that practically speaking, the restrictions would ban climbing."

Park Service officials disagree.

"The plan is not to close off all rock climbing," said Patrick Gregerson, chief of park planning for the national capital region. "It's to close off a few routes that have potential [for plant species] to come back."

Gregerson noted that park officials plan to work with the climbing community to draft a climbing management plan.

The park is at the northern end of the 15-mile Potomac River Gorge, which is one of the country's most ecologically diverse areas with more than 200 rare plant species, officials said. Each year, nearly 500,000 people visit the 800-acre park to hike, bike, ride horses, kayak, rock climb and fish.

Although officials said there is no evidence that climbers have damaged the rare plant life, there is evidence that over time the thousands of visitors who have clambered over the park's ledges have unintentionally trampled tree roots and thinned vegetation. Moreover, officials said they have an obligation to safeguard threatened plant species, at least one of which -- the Nantucket shadbush -- is so rare in Virginia, it can be seen only in the park.

"What we can say for sure is that there are a number of state-listed rare plants that grow within the climbing areas," said Brent Steury, a natural resources program manager for the Park Service. "To what degree they're impacted by rock climbing, we don't know. But if they're there, and they are, the rock climbers have the potential to impact these rare species."

In an effort to reduce that impact, officials released a proposal last month to close off some cliffs to climbers and install static anchors in other locations where climbers could tie their safety ropes in order to climb. Currently, climbers pick their own spots along the gorge's mile-long cliff face and affix their ropes to rocks and trees. The plan also suggests regulating safety and access to the area by requiring climbers to have permits.

The permits, officials said, could require climbers to specify where on the cliffs they plan to be and could help rangers and emergency workers locate climbers in the event of an accident.

Climbers have been enjoying use of the park's 70-foot cliffs since the 1930s, largely unfettered by rules or restrictions.

Local climbers said they would be happy to accommodate reasonable restrictions to preserve the landscape. But they worried that the proposal to limit where they could drop their ropes would not only greatly reduce access to the cliffs and cause crowding but also that the need for permits would be an unnecessary hassle and discourage climbers from visiting the park.

"I don't think anyone intended for [the plan] to have this serious an impact," said John Gregory, 55, vice chairman of the Blue Ridge chapter of the American Alpine Club and a climber of Mather Gorge for 30 years. "I don't think anyone intended to stop climbing. But when you look at the sum total of the effects, that's what's going to happen."

A public hearing on the draft plan will be held at 1 p.m. Saturday at the park's Great Falls Visitor Center. A comment period will follow.

Ledges and cliffs on the Potomac's west side at Mather Gorge draw hundreds of climbers a week to Great Falls Park.