Thanks, all!
I think I have 30 pairs of boots, counting boots and booties. My shoe collection is dominated by boots, and by sandals in the summer. I love that these shelves are easily moved so I can switch out the shoes when the seasons change.
I was a little surprised the shoe collection didn't look more overwhelming, but I did do some culling in the last few months. Another pair of booties and another pair of flats made their way into the "sell" pile yesterday as I put things away. This process has been really great for reevaluating what I have. I can see everything so much better now! It was an interesting realization that my jackets and blazers take up as much room as all my tops. And I barely have any trousers.
There is a space reserved for the Old Gringo black studded cowboy boots.