Some 10,000 black-tailed prairie dogs will be poisoned on the Little Missouri National Grasslands starting in October.

The U.S. Forest Service has been moving toward the decision for more than two years, getting public input and weighing alternatives.

The prairie dogs live in 11 colonies that either already have or will soon move onto private land next to the grasslands. These colonies are on the McKenzie District of the grasslands.

The Forest Service says it won't poison the prairie dogs if the private landowner chooses not to poison them on his side of the fence.

The agency's decision published May 26 says the plan involves roughly 300 acres of land.

District ranger Ron Hacker said he decided on eradication to keep the prairie dogs off private land, protect the colonies from adverse effects and to minimize impact to other species.

The only other alternative was to do nothing.

Five of the colonies will be eradicated altogether and the remaining six will be partly eradicated to create a buffer zone between the colony and private land.

Another 11 colonies will be monitored and possibly eradication, or treatment, would occur on some.

The agency uses "treatment" to describe the action, because the prairie dogs will be killed by putting rolled oats treated with a rodenticide of zinc phosphide in their burrows.

The colonies will be checked and treated again if prairie dogs are still active.

The project will be done between October and December, after migratory birds have moved out, this year and any subsequent years that retreating may be required.

Hecker said the empty burrows will be leveled and seeded.

Any appeal must be filed within 45 days from when the decision was published.