Complex sentence: Rhythmites from the Missoula Floods have also been observed in the Columbia River valley-most notably at locations like the White Bluffs, which are comprised of more thickly bedded deposits in the eddy area behind the Saddle Mountains.
Split into simpler sentences: Rhythmites from the Missoula Floods have also been observed in the Columbia River valley. This is most notable at locations like the White Bluffs, which are comprised of more thickly bedded deposits from the eddy that formed in the floodwaters behind the Saddle Mountains.