UPDATE: I posted it on the Cornell Ornithology FB page, but got no replies. I also posted it in a couple of other places, also with no replies.
I was already pretty certain it wasn't a Greater White-fronted goose; baturn is right about that, the white head just doesn't fit with any images I've seen. So then I latched on to this idea of a blue phase snow goose. Seems closer, but I dunno.
A new poster here, NellyG says he/she is a duck expert and works with them for a living--I pm'ed them and the response I got was that it is just a domestic goose that has possibly bred with a Canada goose.
That's where it stands for now. I have no reason to NOT believe an expert, since *I'm* certainly no duck expert. But...other than the Canada geese, I've just not seen ANY other "domestic" geese out here in this wildlife management area.
So, I'm still not 100% convinced, but it's looking like it may just be an ordinary Goose Goose.
Final Update: Got another look at it this past Saturday, and a slightly better photo. The conclusion from experts: It is definitely a crossbred goose--Canada goose and something domestic. Ah well. At least now I know, and I can stop wasting time trying to get a better photo of it!