The book posted above pertains to a similar model (yes, I’ve finished it Blam, believe me, you *do* want it); those authors look at various current large lakes (including Lake Michigan) and other large bodies of water (Hudson’s Bay) for earlier supporting research on where the impacts happened. There’s quite a bit about the Carolina Bays, offshore Carolina Bays, and similar (basically identical) formations throughout the US and Canada, and used their orientations to find the impact points. Before they did that, they’d found for evidence for extraterrestrial origin of the parent impacts (the bays being ejecta craters), and the “black mat” which caps the Clovis period. Interestingly enough, the black mat appears to correspond to a similar, algal growth phenomenon which left fossil traces after the Permian-Triassic and Cretaceous-Tertiary events.
If you give a complete enough review maybe I won't have to buy it ;^)