I would have gladly made the maps if they would have paid me lol. A truly accurate map would take a lot of Time time because you'd have to analyze individual events each winter and the pns statements that went with them.
These are the sites they report consistent snowfall data:
DTW, FNT, MBS, DTX, ARB. Everything else is relying on coop and cocohras data. While some coop observers are diligent (myself included hehe) others are not. So what you would get is the coop sites that were filled with missing data, or would call a snowfall that had melted or sublimated a trace by their observation time, are going to have much lower totals than other nearby areas. So when you take all those numbers and make a map. You're making all these weird squiggles and circles to try and make it make sense when it doesnt. As stebo said. Nothing is better than somethinh wildly inaccurate data. Coop observer data is often notorious for lowballed snow data, so there's little accuracy to the actual accumulated season total data.
Now they do have an archive for all their event writeups which is great because you can see the haves and have not for individual events.