Pennsylvania’s Icy Cliffs Offer a Chill Challenge : Adventure: Attacking an ice-covered precipice with crampons and ice axes takes a special breed of climber.

The ice-covered cliffs rising high above the Delaware River north of Philadelphia provide a special challenge to a growing number of climbers who are linking up via Internet.

They are ice climbers, adventurers who scale slippery slopes just because they are there.

And the north-facing slopes at Kintnersville provide what one climber calls “the most reliable southern ice in the East.”

On a recent winter’s morning, four experienced ice climbers--Mike Flood, Mark Ronca, Mark Gravatt and Ed Van Steenwyk--gathered here to practice their risky art.

Just last December, Flood was sitting in the climbers’ base camp on the slopes of the active volcano Popocatepetl outside Mexico City, trying to decide if there was too much sulfur gas in the air to make his ascent.

Ronca had just returned from a climbing trip with a friend to Switzerland and France. Gravatt plans a trip to ice-climb in Utah and rock-climb in Arizona.

And Ed Van Steenwyk has been teaching learning-disabled students English in a classroom in Bryn Mawr, Pa.

All were thinking about climbing.

Strapping crampons (spikes) onto his hiking boots, Van Steenwyk, 33, of Lawrenceville, N.J., looked up into an amphitheater of “fat” ice rising above the Delaware.

“Apart from work, this is what people like me do,” he said.

Attacking an ice-covered precipice with crampons and ice axes takes a special breed of climber.

“There’s a great deal more to know about ice than there is about rock--the temperature, the thickness, when it will fall--whereas rock is very stable,” said Ronca, 23, a carpenter from Springtown, Pa.

Gravatt, a 28-year-old employee of an outdoor adventure experience company from Lake Harmony, Pa., called the climbing here last year “fantastic.” But this season, with its mild temperatures and little snowfall, has taken a little of the gleam out of these climbers’ eyes.

Flood, 37, a climbing instructor from Frenchtown, N.J., tugged on his gloves as he surveyed the cliffs above him.

“On one climb,” he said, “I hit my ax into the ice and a column of running water came shooting out three feet into the air.”

Ronca felt no apprehension about his climb. He has been climbing these same rocks since he was 14, and scaling them when they were ice-covered for the last five years.

Ronca and the other climbers don’t take unnecessary risks. If the ice doesn’t look safe, if the weather hasn’t been cold enough for long enough, or if it just doesn’t feel right, they don’t climb.

And they all have the right equipment. Basic climbing, safety, and cold-weather gear for ice climbers can run between $1,000 and $1,500.

Van Steenwyk looked with disdain as another climber halfway up the cliff fell several feet onto an icy plateau. “There’s no excuse for that,” he said. “This isn’t that hard.”

The four climbers are not gonzo MTV-generation thrill-seekers. They are experienced athletes who love the outdoors and love adventure. And Flood is doing his best to make that image stick.

He sent out a mailing to 750 climbers across the East and as far west as Ohio in hopes of organizing a climbers’ coalition.

“The number of climbers has increased 20 to 40 fold in the last five years,” Flood said. “I see 100 postings a day in the Internet from climbers trying to connect with each other.”