Mary was landing on Rwy 31 (which the AWOS made clear the winds
were favoring), while another pilot was landing on Sky Harbor's Rwy 13 (?)
just three miles away -- which seemed pretty bizarre.

It does, till you're heading in to one and hear someone on the frequency aiming
for the other. Heads up! They're so close, it kinda makes sense to have them
on the same freq, in case you don't have 2 radios to monitor traffic at the
other strip, which could wander into your pattern. I love Sky Harbor, even
though I couldn't spot it the first time I went there until I saw a floatplane
landing on the "runway" next to it...in Duluth Harbor!

There's nothing like flying downwind for Sky Harbor's runway 14 and looking out
over that vast lake. You can't see the far shore and just as you think how cool
it would be to go fly out over it you hear the strains of Gordon Lightfoot's
"Wreck of the Edmund Fitzgerald" in your mind and realize how cold and hungry
that water looks...it's about 40 degrees year-round, and has the greatest depth
of any place in North America. Don't ditch. You won't last long treading water.

Is the restaurant on Bong Field (nautical themed, with a few nods to aviation)
closed now? Is Barker Island another length of the Park Point strip that
shelters the harbor from the lake?

If you ever get a hankering to go even further north, Ely with its wolf museum
is a wonderful destination. Feels like you're at the top of the world, and the
sectional will warn you of the areas where the concentration of iron ore in the
ground tweaks your compass...