Yellowstone Falls

WordReference Random House Unabridged Dictionary of American English © 2025

Yel′lowstone Falls′, 

1. Place Names two waterfalls of the Yellowstone River, in Yellowstone National Park: upper falls, 109 ft. (33 m) high;
   lower falls, 308 ft. (94 m) high.

Collins Concise English Dictionary © HarperCollins Publishers::

Yellowstone Falls noun:plural

1. a waterfall in NW Wyoming, in Yellowstone National Park on the Yellowstone River