California park officials warned that the Plumas-Eureka State Park in southeastern Plumas County could be closed to campers until early next summer. The warnings follow the discovery of bubonic plague-infected rodents at the park. Officials closed Upper Jamison Campground at the park after laboratory tests confirmed the presence of the deadly disease. Park spokeswoman Mary Hawkins Rogers said heavy rains could delay plague treatment until spring, forcing the park to remain closed for camping. So far, only the park’s 67-unit campground has been closed. Hiking trails and a museum remain open to the public. The 5,000-acre state park has a history of problems with bubonic plague, which is spread to rodents by fleas.