I feel weird calling people employed by my employer but whom I don't normally interact with "co-workers".

I tried "teammates" but that, I think, means something even closer.

So… suggestions? Does "colleagues" sound like it means a different group than "co-workers"?

I work for what is similar to a school "district," but not geographically based. The quickest driving route to visit all our locations and return to your starting point would 1000 km and our team is more distributed than that. I interact with 3/4 of the staff only a few times per year.