The road distance between Mysore and Ooty is about 164 km. It takes about 4-5 hours travel, from Mysore to Ooty by road.
Mysore to Ooty by Road: Let’s first see the driving directions for those of taking your car/bike to Ooty from Mysore. You can also travel from Mysore to Ooty by bus and shared private maxicab services.
Mysore to Ooty via Masinagudi ( distance 136 km ): Mysore City —- 24km — –> Nanjangud — 43km –> Gundlupet — 20km –> Bandipur National Park — 8km –> Karnataka Tamilnadu border — 5km –> Theppakkadu (leaves NH67) —- 7km –> Masinagudi — 8km –> Ghat section starts ( 36 hairpin bends ahead ) — 14km –> Joins NH67 (Ghat section ends) — 7km –> Ooty
Mysore to Ooty via Gudalur ( distance 183km ): Mysore City — 24km –> Nanjangud — 43km –> Gundlupet –20km –> Bandipur National Park — 5km –> Karnataka Tamilnadu border — 7km –> Theppakkadu — 17km –> Gudalur Town — 46km –> Pykara Lake — 21km –> Ooty
So its actually two routes to chose from after Theppakkadu.
One goes via Masinagudi and the other via Gudallur town.
The first looks a bit shorter , but a lot tough to drive thanks to the steep climb and those hairpin bends. Irrespective of the route, the road quality is pretty decent all the way from Mysore to Ooty.
You can use the same routes to travel from Mysore to Wayanad region in Kerala and also to places like Himavad gopalaswamy betta, Mudumalai etc.