Cumbria Police say the A66 will remain closed at Threlkeld "for the foreseeable future".
Diversions are in place.
People travelling from Keswick are asked to travel along St Johns in the Vale.
Those travelling from Penrith, will be turned round at Rheged and are advised to use the M6 routes.
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A look ahead at the forecast for the Border region
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A look at the forecast for the Border region.