The Loue valley is most easily reached from Besançon, the capital of the Franche-Comté, which is about 25 kilometres north of Ornans and served by TGV from Paris (about 2 hours 20 minutes). From Besançon, a car is almost essential for exploring the valley properly — the villages along the river are small and public transport is limited. Ornans has a bus connection from Besançon but services are infrequent.
Cycling is an excellent option: the valley has marked cycle routes, the gradients are manageable, and the distance from Besançon to the source and back can be done in a long day. Bike hire is available in Besançon.