Why is the concrete trail on the other side of the creek closed with a ‘No trespassing” sign.

Full statement from the park can be found here: https://www.olivernaturepark.com/information-regarding-bridge-closure-oliver-nature-park

It's closed until the dispute is settled

There is a no tresspassing sign related to the private homes abutting the walk way but when i was there 3 months ago the walk way was open. Go on their web site an inquire.

Current court case pending. Mansfield City Hall on FB has more details.

There is some sort of neighborhood/city legal dispute.

I believe that is private property.