Kunzum La isn't open all year
Kunzum La, Spiti Valley (Kaza), Himachal Pradesh
The Manali side route into Spiti crosses Kunzum La, which is snowbound for a large part of the year. Outside the summer window, the only practical way in is the long road via Shimla and Kinnaur.
The lesson
Decide your direction into Spiti only after checking which passes are open that week.