GINGER VALLEY, Afghanistan ? For the British Royal Marines camouflaged in rock crags and under brittle trees on this mountaintop near the Pakistan border, last month’s American offensive may seem like ancient history. The mission the deadliest thus far of the war took place in this very location, but the marines who now occupy the area haven’t seen a soul in days.

But a reminder remains: Sitting atop the mountain’s highest point known as Objective Ginger is the MH47 Chinook helicopter that was forced down during the fighting in early March when U.S. troops tried to land.

Seven Americans died in the fighting when the helicopter came down, and the badly decomposed bodies of several suspected al-Qaida and Taliban fighters still lay amid rocks and Chinook parts.

The British-led mission, dubbed Operation Ptarmigan, is the first large-scale operation since the U.S. Operation Anaconda, and it serves as a reminder of how arduous is the task of clearing such thick, massive mountains of hostile forces.

Allied forces have been through the general area, known as the Ginger Valley, several times, but leaders of the coalition say there is still intelligence worth gathering and that it is important to deny al-Qaida and Taliban forces what has historically been a key resupply route from Pakistan.

“It’s like clearing the Alps,” said Maj. Bryan Hilferty, a U.S. military spokesman at Bagram, a key allied base in central Afghanistan. The Royal Marines’ main fighting force which will soon number 1,700 has been based there since they began arriving in Afghanistan a few weeks ago.

Operation Ptarmigan, which also involves much smaller numbers of American and Afghan troops, is the Royal Marines’ first combat mission in Afghanistan, and their first major mission since the 1982 Falklands War. A ptarmigan is a type of grouse found in Scotland that is known for blending into its environment.

Two days into the operation, marines at the 10,000-foot-high (3 kilometer-high) site said Wednesday they hadn’t had any contact with their enemy, but had found thousands of rounds of ammunition, communication equipment and some documents in caves and bunkers; hide-outs that they then destroyed. The caves and bunkers were in the valley below, a corridor forces call “a rat line” through which they believe al-Qaida and Taliban transported and may still wish to transport supplies from Pakistan into Afghanistan.

The intelligence value of the items found wasn’t immediately known, but the marines emphasized that they had achieved one of the mission’s main goals by securing the area. U.S. forces have been in the area since Anaconda, but only briefly.

“A lot of these caves have been used for centuries, and have been developed and expanded. When we pull out, the al-Qaida and Taliban could come back in and set up shop so they can export terrorism to our countries. Since we’ve destroyed them, they can’t establish themselves in the same way,” said Sgt. Major Russ Craig, of the Royal Marines’ 45 Commando.

As the sound of mortars firing at bunkers and enemy mortar positions echoed off the mountain walls, marines in camouflage fatigues and painted faces guarded their positions in shelters set up under netting. For the marines, among Britain’s most highly trained troops, the mission was also an important test; with one or two exceptions, none of them have actually been in combat situations before and their superiors wanted to see how well they could adjust to the climate and coordinate.

Wearing heavy, bulletproof vests and other gear, the marines seemed to manage the rocky, steep incline easily and credited the high-altitude training they do regularly in Scotland.

The mission was considered relatively low risk, as a much smaller group of marines had come into the area on foot last week and observed whether there was much al-Qaida and Taliban activity before the bulk of troops came in. Regardless, the marines were performing as though they were on guard.

Some said they were disappointed there hadn’t been any fighting.

“It would be a shame to come all this way and not have any contact all the lads have trained for it,” Andrew Robertson, 24, a marine from Glasgow, Scotland, said from a little stone shelter where he had spent the past two days.

With the Chinook a few feet (meters) up the hill, Robertson didn’t have to look far to be reminded of recent fighting on this mountaintop, which overlooks dramatic valleys of red rock and soaring, snow-covered peaks.

“When you’re in a helicopter, you like to think you’re just going from point A to point B and nothing’s going to happen to you,” he said. “It’s not brought home until you see the results like this.”