breaking up into regions worked for me when I ran a pet rescue transport.
Folks who wanted to volunteer to drive rescue dogs signed up in their region so when someone needed a volunteer they went to the area they needed. easy.
I do find it a bit difficult to navigate thru everything in the way the section is now. If I'm interested in a thread I subscribe. but if a new one pops up and I miss it - odds are it gets buried fairly easy too