11.   The Park Service stresses that there is no marked trail and that flash floods and hypothermia are constant threats.

12.   Tours of the park are self-guided, with marked trails and paved walkways.

13.   A British woman skiing off the marked trails in dangerous conditions was killed and another hurt Tuesday in an avalanche, police said.

14.   A British woman skiing off the marked trails in dangerous conditions was killed and another skier hurt Tuesday in an avalanche in the French Alps, police said.

15.   A marked trail keeps cavers from getting lost inside the bewildering maze.

16.   Authorities are warning skiers to venture off marked trails only with extreme caution after recent heavy snowfall increased the risk of avalanches.

17.   In an effort to prevent deadly avalanches, authorities in the French Alps have banned skiing and hiking off of marked trails for four days.

18.   The discovery brought an end to the search for a group of six people that went missing Monday after they went skiing off marked trails.

19.   The Italian news agency ANSA said the victims had been skiing off marked trails.

20.   The skier, who was not identified, was skiing off marked trails Tuesday when hit by an avalanche.