Here are some US National Parks Links to the Ancient Lake Florissant
This is another one of those interesting natural phenomena areas for which a localized flood-sedimentation event story has been created to brush away any hint of a global extinction event by a disruption in the minerotrophic hydrological cycle, no matter how one wishes to spin the catalyst for it's trigger.
Take a look at some more pictures of these massive Redwood Fossils and take note that many of these global fossils finds and locations for whatever reason appear to have some type of giant redwood or cypress as the foundation tree of thsee extinct forest.
A blogger-Geologist Steven Veatch has a Colorado Earth Science site where he has put alot of effort into explaining some of the phenomena surrounding the amazing finds around this unique area. Here is his site and below that I'll post some maps he has done of the areas in question.
NAPP vertical color infrared (CIR) aerial photo of the Florissant valley from 20,000 feet (9/24/88). Color infrared film is used to interpret natural resources such as vegetation, soil conditions, water resources, and other features. Active vegetation appears in various shades of red and pink (intense red colors indicate vigorous and dense growth). Water that is clean and clear appears black. Shallow water reflects bottom sediments and appears in various shades of blue. Soil conditions (moisture levels) are revealed by the degree of the gray tone: dry soils are light gray, moist soils are gray, and wet soils are dark gray. Top of the photo is north.
Below are some of the ancient lake bottomlands which are even in some ways are similar to the Buchanon Lake Formation of Axel Heiberg Island. If you recall at Axel Heiberg, that there was a definite stump field where the trees grew and for some unexplained sudden catastrophy the massive tree trunks were snapped off much like the event at Mount Saint Helens, but in the Arctic case they were burried in tons of sediment debri under this formation. Notice that the Florissant site exhibits similar stump fields, yet I am unaware if anyone has attempted to explore and uncover any petrified logs that may be intact or partially intact in these similar depression areas.. But decide to yourself.
One can only imagine what that ancient pristine plant rich vegetative world would have looked like and what could have been.