WordNet (r) 3.0 (2006):

Yellowstone
    n 1: a tributary of the Missouri River that flows through the
         Yellowstone National Park [syn: Yellowstone, Yellowstone
         River]

U.S. Gazetteer Counties (2000):

Yellowstone -- U.S. County in Montana
   Population (2000):    129352
   Housing Units (2000): 54563
   Land area (2000):     2635.154295 sq. miles (6825.018002 sq. km)
   Water area (2000):    13.898206 sq. miles (35.996187 sq. km)
   Total area (2000):    2649.052501 sq. miles (6861.014189 sq. km)
   Located within:       Montana (MT), FIPS 30
   Location:             45.816535 N, 108.460718 W
   Headwords:
    Yellowstone
    Yellowstone, MT
    Yellowstone County
    Yellowstone County, MT