What happened to my missing directories

I have a multisite running 8 domains under it. The directory structure is set up as "public_html/wp-content/uploads/sites". Under "sites" I have domains 2, 3, and 6 but sites 1, 4, 5, 7, and 8 are missing. I've not been able to find their directories anywhere on the server. The sites are functioning and I'm able to access them from my dashboard and do all maintenance except I can't find their directory when I have a specific need to upload something directly to them. Anyone have a suggestion for why I can't find them?

Thanks,
Larry