Deer Lodge sits on Interstate 90 between Butte (75 km southeast) and Missoula (100 km northwest). Both cities have small commercial airports with regional connections, and either makes a sensible base for a fly-and-drive trip. Bozeman Yellowstone International Airport is around 280 km southeast and has more frequent flights from major US hubs.
Greyhound runs limited daily service on the I-90 corridor with a stop in Deer Lodge, but a car is essential for getting to Grant-Kohrs Ranch outside town and for exploring the surrounding valley. The 1909 BNSF (formerly Northern Pacific) station downtown is no longer served by Amtrak — the Empire Builder runs the northern route, well to the north. Local parking is free.