Douglas Wielfaert The Nursery Rocks of Yellowstone’s Lamar Valley Posted on June 5, 2021 Rocks of granite deposited by glaciers in the Lamar Valley of Yellowstone National Park by glaciers, are called glacial erratics, and serve as nursery rocks to Douglas fir trees. Read More Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Pinterest (Opens in new window)Click to print (Opens in new window)Like this:Like Loading...