In the year 1965 it was possible for agate collectors to collect fine agate-specimen at the road construction site of the Interstate 55 in the area between Union Road and Lindbergh Boulevard in Saint Louis.
Their structure is looking similar to the structure of the agates of Teepee Canyon. The core of the agate-bearing boulder is showingy classical banded agate. This core is covered very often by a thick crust of flint. The Banding is usually broad and weak, the colours are from pale yellowish, pinkish or greyish tones. Very seldom some agates are showing finer banding or strongly contrasting intensively colours.
More information about agates from this locality is given at www.thies-times.com