Clarkia fossil beds

The fossil beds were laid down in a lake roughly 15-million-years ago, when a drainage basin was dammed by the flood basalts of the Columbia River Plateau.

Narrow and deep, the lake's cold, anoxic water and rapid sedimentation created perfect fossil conditions.

The fossils indicate that the region's climate was much warmer and wetter than today's, and similar to that of southern Florida.

Their preservation is exquisite; fresh leaves are unfossilized, and sometimes retain their fall colors before rapidly oxidizing in air.

[1][2] It has been reported that scientists have managed to isolate small amounts of ancient DNA from fossil leaves from this site.