Uttarkashi, 155km from Rishikesh and the largest town in northern Garhwal, is a major stop on the road to Gangotri Temple and the Gaumukh Glacier trek. The main bazaar is worth a wander and has all the supplies you might need. A number of outfitters can arrange treks in the region, including to Tapovan (beyond Gangotri/Gaumukh).
The town is probably best known for the Nehru Institute of Mountaineering, which trains many of the guides running trekking and mountaineering outfits in India. The centre is across the river from the main market and has a museum and outdoor climbing wall. Basic and advanced mountaineering and adventure courses are open to all – check the website for details and admission information.
Uttarkashi also hosts the Makar Sankranti festival.