the northwest and rises in elevation and then descends at St. Donatus. North of St. Donatus, the highway travels and enters the Dubuque area. At the unincorporated community of Key West near Dubuque, US 52 north turns south in a wrong-way concurrency onto the expressway carrying US 61 south and US 151 south. After traveling with the other two routes for , US 52 exits at a folded diamond interchange onto the Southwest Arterial, a , four-lane expressway. There is an overpass carrying Military Road, then a dogbone interchange with North English Road. After passing through the roundabout of a half-dogbone/half-diamond interchange from the US 20 expressway at the end of the arterial, US 52 passes over the US 20 expressway and merges onto its westbound lanes. The Southwest Arterial is largely freeway in character, however neither of its termini are free-flow interchanges. US 52 north is co-signed with US 20 west for , passing through the Dubuque County exurbs of Peosta, Epworth, and Farley before exiting north onto Iowa 136 in Dyersville. It follows this north-south route through New Vienna, passing near the Field of Dreams filming site, until the northern terminus of Iowa 136 in Luxemberg. From Luxemburg, US 52 heads north towards Guttenberg. As it approaches the Mississippi River, the road reenters the Driftless Area. After crossing the Turkey River, the highway rises nearly in elevation before descending again at Guttenberg. North of Guttenberg, US 52 rises out of the Mississippi valley and travels west and then northwest away from the river. North of Garnavillo, it intersects Iowa 128, which serves as a cutoff to Iowa 13 near Elkader. later, it intersects Iowa 13 at its northern end. north of the Iowa 13 intersection, US 52 intersects US 18. Between this location and Calmar, US 52 runs parallel to the DME Railroad. The two highways travel together to the northwest for through Monona and Postville. At Postville, US 18/US 52 intersect Iowa 51. On the west side of Postville, US 52 splits away from US 18 and heads to the northwest towards Calmar. At Calmar, US 52 turns to the north at an intersection which is also the eastern end of Iowa 24 and the northern end of Iowa 150. It heads to the north-northeast for to an intersection with Iowa 9 on the southwest side of Decorah. From Iowa 9, the route crosses the Upper Iowa