Heya Chris,
I'm pretty new to the forum also, and also in Lincoln.
Im sure that you know the following but JIC:
Izaak Walton has a 300 yard range
Eastern Nebraska Gun Club has a 600
The one in GI that Hornady donated to is either 600 or 1k (600 IIRC)
You can try linking up with Heartland Rifle (the civilian part of Tier III Ops) where they have classes on farmer's land going to 1k and one for sure that goes to 1 mile. They have sustainment training sessions where you pay $75 and I believe they MAY spot for you (sorry, I am away from my notes to give you better answers).
I'm in the process of building a 900 yard range across the corner of the pasture on our plot across the border. When I get that up and running (later this summer hopefully) I'll PM you if you'd like.
Welcome aboard!