 It enters the state near Lamoni from Missouri and continues north through the southern Iowa drift plain.In the Des Moines area, I-35 is overlapped by I-80 and the two routes bypass Des Moines to the west and north.I-235, the only auxiliary route of I-35, serves the suburbs and downtown Des Moines; it begins and ends at the two interchanges where I-35 and I-80 meet.