MovingUpintheWorld

Migrationsdon’talwaysstretchacrosslongdistances.Somemigrationsmoveupanddown.

Dallsheepliveinsomeofthemostrugged,hostilelandinNorthAmerica.Theymoveastheseasonschange.Buttheirsisaverticalmigration.

Inspringandsummer,Dallsheepgrazeinhigh-mountainmeadowsandonopenslopes.Theynibbleongrassesandawiderangeofotherplantsthatareplentifulinsummer.

Beforewintercomes,thesheepmovedownthemountain.Howdotheyknowtheway?Scientiststhinkthatthepathispassedonfromgenerationtogeneration.

Theoldestsheepusuallybeginsthemigrationandleadstheothers.Theydescendabout1,200 meters(about4,000feet)downrocky cliffs.

Dallsheeparenotgreatwanderers.Mostspendtheirentirelivesinthisnarrowband,upanddownthe mountain.