...the everlasting and crowning glory of the Gorge is the silent majesty of the mighty Columbia itself. In the areas of the past it was this then greater river that had worn down through thousands of feet of Columbia basalt, layers of andesite, cemented beds of Satsop gravels, Carson lavas into the Eagle Creek Formation, the lowest stratum so far exposed.
In this base formation lying beneath the thousand of feet of later formations, there are strata of alluvium encasing fossilized leaves and the petrified trunks of trees as evidence of a flora that flourished in this area thousands, perhaps millions of years ago. In 1871-73, Professor LaConte identified the leaves of two oaks, and one conifer, found at the mouth of Moffett Creek. Later on J. S. Diller of the United States Geological Survey, added to this list both poplar and maple leaves.1 In 1915, when the Eagle Creek trail was being constructed, not far from the Columbia River Highway, a fossil bearing bed was opened up by the Forest Service and Dr. Ralph [K. ?] Chaney, then of the University of Chicago, collected many perfect specimens, of types that still flourish upon the earth, although the individual species found in these ancient beds are now extinct. The specimens found were, "maple, black oak, sweet gum, smilax or greenbrier, elm, walnut, sycamore, magnolia, sumac, cherry, poplar, hone-ceam, birch, alder, pine, and almost certainly spruce, chestnut and willow. What luxuriance of forest must this have been! And though of types that yet flourish upon the earth, the individual species found in these ancient beds are now all extinct 2".
Identical specimens have since been found by Dr. Chaney, now of the University of California, in a stream of stratum of sand and clay in the face of the gravel cliff along the descending curve of the highway, just west of Tanner Creek. Sometime, somewhere in this vicinity, there grew a forest of the listed trees whose leaves budded in a distant spring time, ripened in a succeeding autumn, fluttered down upon a stream and were imbedded [sic] in its silts, just as they do today, to be unearthed and identified by the genius of mankind, millions of years later.
Here in July 1926, Dr. John C. Merriam, of the Carnagie Institute, was studying the fascinating geology of this locality with a party of scientists and students. A student uncovered a specimen of the ancient Gingko tree "originally known as living only in groves about the ancient temples of China and Japan." A very interesting story of this find is told in Dr. Merriam's "The Living Past" Chapter III, p.p. 41-54. Later on he brought from Washington D. C., specimens of this ancient tree and had them planted, some near where the leaf was found, others at the west end of the gravel cliff. In 1942 the small Ginkgo tree at the upper end of the cliff was growing thriftily, and bid fair to become a tree where this species flourished so long ago. Unfortunately, in June 1945, it was found the crowding of the highway area by Bonneville workers had destroyed the tree. The fossilized leaves that have been identified, and the visible, petrified trunks of trees embedded in the gravels of this underlying Eagle Creek formation are indicative of the great antiquity of the exposed base of this geologic structure.