gravity - What's the evidence, if any, for some local concentration(s) of dark matter in some region(s) smaller than a galaxy?

What's the evidence, if any, for some local concentration(s) of dark matter in some region(s) smaller than a galaxy?

Galactic-sized - or larger - gravitating halos seem to get all the attention. I'm just wondering about the status of smaller halos/concentrations, if any.