"Rivers of Arctic Alaska, as they perpetually cut through the prairies of the Pleistocene Ice Age. Ancient remains of certain extinct fauna is common in these rivers that thaw the permanent ice under the grasses and tundra. Every summer season exposes tusks and bones in these rivers and gravel bars that still remain in organic condition due to a constant frozen condition known as permafrost. By exploring these streams and rivers, it is well noted that specimens are not deposited deeply in the tundra but a mere few feet below until they are exposed by thawing conditions and erosion. Tons of fossils, preserved in ice are lying in the gravels, mud, and cut banks of these systems every summer"