A Highlight of any Yellowstone trip is visiting The Grand Prismatic Spring, the third largest hot spring in the world and the biggest in the United States.

Its bright rainbow colours from deep blue to rust red really are great to see, and probably best viewed from above for the best effect. We were only able to view from the boardwalks as sadly the trail up a nearby hill giving a good overlook of the spring was closed due to maintenance.

The spring is 50m deep and 110m across and releases 2000 litres of water every minute.