Be careful. In my part of the country there are old hand dug wells. In particular there was one on the farm and the old well house was missing. The former land owner placed boards over the hole (not the best way to handle the hazard). Over the last 50 years the well slowly filled itself in.
I agree with those that say get the wood out. Filling with sand is the best option if it is readily available. Sand settles less than soil. I would mound the sand just as Egon said.
I agree with those that say get the wood out. Filling with sand is the best option if it is readily available. Sand settles less than soil. I would mound the sand just as Egon said.