Dictionary.com
Thesaurus.com

Stone sheep

British  

noun

  1. a wild sheep found in the Yukon and the northern Rocky Mountains

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of Stone sheep

C19: after the US naturalist Andrew Jackson Stone, who first discovered the breed in 1896