Much of the fencing has disappeared within the last few days from two sites at the tree-obscured beauty spot, leaving yawning gaps.
The thefts have infuriated locals and volunteers, like Friends of the Valley spokesman Philip Thomson who commented that the “senseless damage” runs into many hundreds of pounds and reinstatement will cost even more.
The vandalism comes at a time when volunteers are striving hard to improve the Redcar and Cleveland Council-owned Valley Gardens for the benefit of the public and the town’s thousands of visitors.
Mr Thomson said, "It’s a great disappointment that a fine community asset like this is being vandalised in this way."
Woodland volunteer Mr Thomson, who’s also a borough councillor, says the latest incident has seen about seven metres of six foot high fencing vanish at the currently closed Woodland Centre.
And, in an earlier theft, many more metres of fencing paid for by grant aid arranged by the Friends of the Valley was ripped from the edge of a meadow near the railway viaduct in the valley - leaving just a gate forlornly standing on its own.
The Woodland Centre, which the borough council plans to lease to a community interest concern, is currently still the responsibility of the council.
Cllr Thomson said: “We’ve reported both thefts to the police and the council.
At present, the Woodland Centre is not in use but is due to reopen and a community ranger visits. A large section of fencing has been stolen there, apparently to be used as firewood. Youths gather regularly in the woods to drink alcohol and set camp fires. But these fences are valued community resources put in place for the enjoyment of the community. They are worth several hundred pounds, but there’s also the cost of replacement which in this steep valley, is difficult.”
In a separate previous incident, fencing near the railway viaduct was taken.
Cllr Thomson said this was funded by Friends of the Valley with a grant.
Members are now discussing whether funds can be generated to replace this, or not.