A mass of white chalky rocks jutting up from the flat landscape. Imagine the chalk covering the entire landscape and then imagine it as the bottom of a shallow sea! You can drive right up to them and walk around and inspect the rocks.
They are clearly chalk deposits and contain a lot of fragmentary fossil material (shells mostly). I didn't find any mosasaurs! I'm convinced, however, that if I had some time to spend here I could find some interesting stuff (it's not a collecting site, however).
My wife and kids give some idea of the scale of the outcrops. Erosion has carved them into interesting shapes. If you're ever driving by on I-70, it's worth the hour or so side trip to visit.