Chamoli is Garhwal's heavyweight district. Badrinath, Auli, Hemkund Sahib and the Valley of Flowers all sit within its borders, which is why itineraries here read like a greatest-hits tour of the Indian Himalaya.
The Valley of Flowers is the classic walk. You reach it by bus to Govindghat, then a mule-and-pilgrim climb up to the Ghangaria base, and finally a day-walk into the valley itself, where the meadows change colour week by week through the monsoon, with blue poppy and Brahma Kamal at the peak of the July to September bloom. Permits are needed, and most people pair the valley with the glacial lake at Hemkund Sahib, a steep day up from the same base.
The whole district strings into one circuit: Auli's ropeway and ski slopes with Nanda Devi filling the horizon, the flower valley, Hemkund, and finally Badrinath, the Char Dham shrine 51 km beyond Joshimath, open roughly May to November. Winter flips the emphasis, the pilgrimage closes and Auli becomes India's most reliable ski hill.
Two cautions come up again and again: the Rishikesh to Joshimath road is long and slide-prone, so budget a full day each way, and everything above Govindghat runs on foot or mule, so pack accordingly. The reward is that no other district packs this much of the high Himalaya into a single week.