Huh. Always just heard it as "Mille Lacs" (Mill Lacks) rather than "Lake Mille Lacs".
I hear/see both. The real shibboleth is if someone calls it by its official name of "Mille Lacs Lake", which THAT term is never used here outside of official DNR contexts.
To help me remember, I just recall that the name means "Thousand Lakes Lake" or "the lake of a thousand lakes", to put it more poetically.
I was up near the Canadian border in Minnesota last week and holy cow is the Rainy River watershed flooded! Historic water levels all over the place. There were actually crews working on Memorial Day weekend to raise the roadways surface out on TH 11 as it starts to peter out among the resorts on Rainy Lake to maintain access.
And out on the water, it was truly bizarre. One can drive a boat through the woods in many places. All of the shoreline marshes were completely underwater and woe be to the property owners up there with improvements built at the water's edge. Everyone's boat houses were half submerged.
Made for tougher fishing; fewest pike I've ever caught on a fishing trip to northern Minnesota. Found some walleyes in a few spots and decent crappie bite, but at times, we were catching fish on what should be dry land.