The Forest Service has developed regulations to keep 35 of the most dangerous noxious weeds out of Idaho’s national forests.

Under the proposal, which the Forest Service hopes to have in place by January, outfitters and hunters would be able to bring hay for horses into national forests only if it is certified weed free.

The rule also would cover straw used for bedding, fire rehabilitation efforts and erosion control by ski areas and road agencies.

Noxious weeds - plants with no natural predators - can take over entire ecosystems, making mountain meadows useless to elk and mule deer and wetlands useless to ducks and other waterfowl.