A short drive off of I80 and close to Omaha, Eugene T Mahoney State Park is convenient if you are passing through NE.  It is a large park with more than one campground.  Since it is close to the freeway there is the constant sound of traffic.  It isn't intolerable, but definitely noticeable.  There are lots of trees and the area is very pleasant.  

This is more than a campground.  There are many activities ie. golf, hiking, fishing, biking etc.  There is a lodge, cabins in addition to the campgrounds.

The sites are spaced well and have plenty of shade.