Updated

After falling out of the sky and sleeping in the mud, American paratroopers grabbed a strategic air base on Thursday and began plotting how to cross 80 miles and thousands of Iraqi troops to seize invaluable oil fields in northern Iraq.

"Kirkuk is key," said Maj. Mike Hastings of the Army's 173rd Airborne Brigade. "The Iraqis want it, the Kurds want it, the Turks want it and various other ethnic groups also want it.

"What this drop means is that we can secure it until we are relieved by other forces," he said. Nearly 50 percent of Iraq's vast oil supplies are pumped in the northern fields of Kirkuk and neighboring Mosul.

More than 1,000 troops parachuted into Iraq late Wednesday, accompanied by tanks and Bradley fighting vehicles. It took hours to dig out the behemoth weapons after they plummeted into vast mud fields created by heavy rainstorms.

A C-130 transport plane landed Thursday, as did 200 more Americans soldiers as the Army began stockpiling the airstrip near Bashur with weaponry and supplies.

Warplanes from U.S. ships in the Mediterranean patrolled the skies over the north as transport planes came in. One sortie of aircraft struck Iraqi mortar and artillery positions.

"Now, with paratroopers in control you can start flying in the various armored vehicles and various support you need to expand your operations," said Rear Adm. John C. Harvey Jr., commander of the battle group including the aircraft carrier USS Theodore Roosevelt.

The paratroopers descended because Turkey, a longtime U.S. ally, has refused to allow some 60,000 U.S. ground troops to cross into Iraq. That left coalition troops with no northern front.

That changed Thursday. American troops began the day wearing muddy uniforms tinged with frost. They fanned a valley nestling the airstrip, surrounded by snowcapped mountains.

By midday, an Iraqi hilltop position had fallen. From that site, Iraqi troops had fired on Kurdish civilians since the 1990s.

In the checkpoint town of Chamchamal, villagers rejoiced when Kurdish military commanders confirmed Iraqis had fled.

Kurdish militiamen gathered mines from along the road as cheering people walked, drove or pedaled to the site.

"They saw a chance to go up there and they took it," said Rostam Hamid Rahim, a high-level Kurdish military commander.

Abbas Kaka drove a truckload of youths to the abandoned site.

"All the bunkers are empty," he said. "It's all right to go up there."

By nightfall, the Iraqis were believed to have retreated west to Qarah Anjir, 16 miles from Chamchamal. But Rahim said there was no evidence the Iraqis had abandoned other positions between Chamchamal and Kirkuk, 22 miles east

Rahim hoped fellow Kurds would not descend on Kirkuk, which is predominantly Kurdish, without U.S. approval.

Americans fear such movements would prompt the Turkish military to invade northern Iraq. Ankara fears Iraqi Kurds will overrun the key oil fields and create a rich, independent homeland that would inspire revolt among Turkey's own minority Kurds.