If you can find a real entrance, more power to you. Parked at Pioneers and 1st, said the bridge was out and go down Jamaica trail. That trail is nothing bit limestone that follows the outside of the park. We went down the trail a couple of miles and the bridge was out and followed another trail. That ended up turning into a "no bikes" trail and dumped you out on the Jamaica trail. Rode that some looking for another entrance and found the Old Cheney parking, but again, no bikes allowed. I know the bikes are on the opposite side of the creek but never found the right entrance.
The parts we were on were nice, fairly easy with some hills and ravines. Probably way too easy if you are used to technical trails. People we asked had no clue there was even a trail down there.
Will just head into Omaha from now on.