Although Lahaul and Spiti are one district, they have to be reached separately.
Lahaul can be reached from Manali, with the road leading to Keylong. Keylong is also the district headquarters of Lahaul. You will have to cross Rohtang Pass to reach Keylong and this road remains closed between November and May due to snowfall. Spiti is on the other side of Lahaul and is best reached from Shimla via the NH 22. The Highway leads straight to Tabo in Spiti. It is a 9 hour journey and some roads are closed during the winters.
The valley is connected by road to the rest of Himachal Pradesh and other nearby states from between May and November. Regular buses ply from Manali across the Rohtang Pass to enter Lahaul and connect to Keylong as well.
Lahaul is on the route to Leh along the National Highway from Manali. Buses and taxis connect Spiti to Manali across the Kunzum La pass.
The closest Railway station is Chandigarh. From Chandigarh, you can reach Lahaul via Manali and Spiti via Shimla by road. The journey by road would be an approximate of 5 and 9 hours respectively. Alternatively, one can also reach Shimla by train and then take a cab for the onward journey.
The nearest airport to the Lahaul and Spiti Valley is the Bhunter Airport in Kullu. Air India is the major service provider here and has regular flights connecting Kullu to large cities like Delhi, Chandigarh and Shimla. The airport is situated at a distance of 160 kilometers from Keylong. From the airport, Manali lies at a distance of 40 kilometers. From Manali, the valley can be reached in 6 hours by road via taxi or bus. The route passes through Rohtang pass and leads to Keylong.