A woman who broke her leg during an expedition into the nation's deepest known cave dragged herself toward the cave's opening Tuesday as rescue workers rigged pulleys

and stretchers to help lift her out.Emily Davis Mobley, 40, a veteran spelunker from Schoharie, N.Y., was injured Sunday when she was struck by an 80-pound rock in Lechuguilla Cave.

Lechuguilla, 54 miles long and 1,565 feet deep, is about four miles west of Carlsbad Caverns.

"She's moved a lot more than we thought she would," said Carlsbad Caverns National Park Ranger Bill Justice. "She's not moving at a rapid pace for a caver, but she's moving at a rapid pace for a woman with a broken leg."

Park officials and cave experts worked in the meantime to set up ropes and pulleys to help lift her out. The rescue could take three days, they said.

Mobley was in a horizontal section about 11/2 to 2 miles away from the entrance of the cave - a winding, rocky shaft about 1,000 feet long. She will have to move herself horizontally until she's beneath the vertical shaft.