National Bridges National Monument ? A campground at Natural Bridges National Monument has been closed because of bubonic plague detected among field mice and chipmunks.

Plague also has been found this spring in rodent populations at Mesa Verde National Park and Colorado National Monument.

National Park Service officials said there never has been a reported human case of bubonic plague originating from the parks or national monuments.

Several weeks ago, park rangers noticed a large number of dead field mice at Natural Bridges, about 40 miles west of Blanding. Chief Ranger Ralph Jones showed that tests indicated they died from the plague.

Rangers plan to use insecticides to kill fleas in the campground area. Humans usually contract bubonic plague after being bitten by fleas that have bitten infected rodents. The campground could be reopened as soon as next week.