National Park Mystery Photo 1: Wow – This is One Big Boulder!

This glacial erratic is located along a trail in one of our national parks. Do you know where this huge boulder is located? Do you know where it used to be?

A glacial erratic is a boulder that’s been transported by a glacier and deposited in a new location where its lithology doesn’t match the bedrock beneath it. Thousands of glacial erratics are scattered about the surface of glaciated national parks.

Most glacial erratics are so small or isolated that they go unnoticed. Some, however, are very large and very accessible. A few are so conspicuous in the landscape that they have become tourist attractions meriting signage, brochure descriptions, and photo op suggestions. Such is the case with our mystery boulder. See the little sign?

Chances are that a goodly number of Traveler readers have seen this boulder, and that some people reading this article have taken pictures of it. Do you know where this boulder is? Do you know where it came from? The only hint we’ll give you is that it’s situated near a road in an NPS unit.

You’ll find the answer in the comment section below.


It's the Glacial Boulder, situated at the trailhead of the Sevenmile Hole trail in Yellowstone. As I recall, it was dropped off by a glacier several thousand years ago.

I think this boulder is in Yosemite.

Our mystery boulder is located in Yellowstone National Park. More specifically, it's situated along the road leading to the Inspiration Point overlook on the North Rim of the Grand Canyon of the Yellowstone. About 80,000 years ago, an early Pinedale Glacier transported it from the Beartooth Mountains to its present location.

trip to jelly n 1969 from ogden, of 2 adults w/4 kids... n main park near geyser... out on side of road picnikn'.... big bear comin up road feddin car to car.... tnen a pick up truck with 2 adults suddenly jumep out of truck on opposite side... they forgot to roll up window...!!!!!end