It is a common misconception that sidewalks are pieces of concrete poured onto the dirt. This is, in fact, untrue.
Sidewalks should be considered states of mind that form wherever two or three people are gathered together to walk or stroll from A to B and back again. In other words, sidewalks are people, and go wherever people go, even sometimes onto frozen lakes.
In fact, a frozen lake might be the ultimate kind of sidewalk, a literal tabula rasa. A perfectly flat, perfectly white, perfectly flawless plane on which anything can happen, any order can form.
[Do croquet balls have their own sidewalks?]
I kind of reminds me of those famous experiments on certain college campuses, where the landscape designers leave open the field grass until students walk on it, forming paths. Only then, do the planners put down the sidewalks. These spaces are self-organizing sidewalks, places where "desire paths" take the first step.
Of course, the sidewalks I mention are spaces surrounding the Medicine Lake art shanties, the loosely assembled bits of buildings annually dragged onto an unfortunately melty frozen lake in the NW suburbs. There are all types of exploratory people walking around these shanties, and it's delightful to approach a little shack and open the door without knowing what you will find inside. Will it be knitting? Fishing? Map making? Puppets? A group of arctic explorers marooned in a frozen sea?
Apart from opening the door, there is no way of knowing who lives in each house, and one senses that a lost form of neighborliness and a culture of 'visting' can be found on this bit of temporary surface.
[This is a very important shanty. Also, there are no bathrooms on submarines.]
Shanties, though, are particularly good on an icy lake, and have characteristic sidewalks befitting a self-organizing, bottom-up urban collection. For one thing, shantytowns always abound on the most moveable, shakeable, marginal spaces... for example the parts of mountains that fall down in rainstorms, or the sides of train tracks, or the patches of earth in between one thing and another. Some cities in the global south have 'squatters rights' rules that allow anyone to keep their shanty ONLY IF they can build it all in one night, which makes the quick and delicate construction of shanties all the more quicksilver.
Unfortunately, it seems that the ice is melting too quickly beneath our feet. This is the end! Carpe shanty, if you dare.
[Transient ice is only water frozen in place.]