This forum has talked about challenges of calculating density. Here’s an article using a kilometer grid
https://www.citylab.com/perspective/...graphy/591760/
Salt Lake Is one of the dozen metros he uses as an example. Choose city by button in upper left corner and it will cycle through all squares for the area by decreasing density.
https://garrettdashnelson.github.io/square-density/
I think I once saw a map of Salt Lake City proper by census tract showing heaviest population in area roughly State to A / South Temple to Fourth Ave but that comes out about 6th in this grid. Will let you discover number one.