Need run suggestions... I goofed.

[Badbaby05]

Make it around the tree...I did! Shade in the summer and sun in the winter

 

[FiveHens]

I'm sure that everything is more obvious from your perspective, but would it be possible to have the run enclose the base of the oak tree? It would be perfectly doable--you'd just have to expand the hole in the wiring every few years so as not to constrict the tree. They would like having some variation in their run!

ETA: chickens do love some amount of sun to bask in, but it's not a laying requirement

I'd use wire on the top--chicken wire, at least.