Flytippers dumped building waste at the entrance to Wendover Woods, leaving a forest ranger to clear up the mess.
Sunday walkers, cyclists and families were turned away while the Foresty Commission’s Rob Bell moved the rubbish which had been left at the front gate over Saturday night.
The site, which usually opens at 8am, was closed to the public until 10.30am.
Mr Bell said: “It wasn’t the start to my Sunday I was expecting.
“The thoughtless dumping of rubbish disappointed early visitors to the site who wanted to start their day with a bike ride or walk in the forest.”
The pile of rubbish included waste thought to be from a small domestic building project, such as bricks, blocks and soil and plumbing pipes.
The rubbish affected business at the Cafe in the Woods, and owner Jon Warbrick said: “We had a very quiet start. The flytippers obviously thought they’d hit the jackpot when they found the layby, because there are no cameras and it’s very dark there.”
The Forestry Commission in the East of England spends more than £100,000 per year cleaning up flytipping on it estates and makes every attempt to find those involved.
It has been very successful in finding and prosecuting individuals who have been identified from going through the dumped rubbish.