I am about to inherit 26 miles of dark fiber. What do I do with it?

The below is a really sad story. Condolences on the coming trainwreck. I
hope you get someone on staff or on consult that understands outside plant
architecture, because it is much more important and complex topic than you
seem to realize.

OutSide Plant design(OSP) is a specialized field worthy of significant
study. The consequences of getting a OSP design wrong are much harder to
fix than getting a network design wrong. You are designing for *20 years*.
If you are at the point of asking a mailing list NANOG, which, um, is not
focused on OSP expertise, it is a really, really good idea to concentrate
on hiring the best consultant.

I have viewed this train wreck too many times.