This time of year, Iowa drivers often find themselves dodging deer that dart into their path. South of Des Moines this morning, a larger obstacle appeared on the Interstate, as Highway Patrol spokesman Jim Saunders says a mobile home fell off a tractor-trailer on Interstate 35 at milemarker 45 near New Virginia. The home fell into the ditch about 8 A.M. The cleanup effort blocked traffic for nearly two hours. That section of interstate is now open.