A warning from Mendocino County health officials as measles activity rises across California. While there are no confirmed cases in the county right now, public health leaders say travel-related spread remains a real concern. Measles is extremely contagious and can stay in the air or on surfaces for up to two hours after someone infected leaves the area. Officials are urging residents to check their vaccination status, especially since local kindergarten immunization rates are below the level normally needed for herd immunity.