Har Ki Dun Trek

Har Ki Dun is a broad, cradle-shaped hanging valley at the head of the Supin river in Uttarkashi district, ringed by the Swargarohini group and fed by the Jaundhar glacier. The trek is a river-valley walk rather than a climb: from Sankri you drop to Taluka and then follow the Supin upstream through deodar and pine forest, past terraced fields and the wooden-and-stone villages of Gangad, Datmir, Panwani and Osla, before the tree line gives way to grass and the valley opens out. Nothing on the route is technical. What makes it real work is length and repetition: several 11 to 14 km days with a few hundred metres of net gain each, on stone-paved mule track, forest trail and, in the shoulder months, hard old snow on the upper section. The cultural side is not decoration. These are lived-in villages with their own temple traditions, and the trail is a working route for people and livestock. It suits a reasonably fit first-time Himalayan trekker who is prepared for long days and cold nights, and does not suit anyone looking for a short walk or a summit. Camping rules inside the national park have changed more than once since 2018, so the exact campsites your operator uses may differ from any itinerary published a season ago.

• The Supin river all the way in, first from a stone-paved mule track and later from the valley floor.
• Gangad, Datmir, Panwani and Osla — inhabited Garhwali villages of carved wood and slate, with terraced fields still worked, rather than a reconstructed showpiece.
• Deodar and pine forest on the lower days, thinning into open grazing meadow as the valley opens out.
• Kalkattiyadhar's meadow, where the valley finally widens and the head of Har Ki Dun comes into view.
• Swargarohini rising at the head of the valley — the 'stairway to heaven' of the Mahabharata, and the reason this is called the Valley of the Gods.
• The Jaundhar glacier at the valley head, usually seen from a day walk out of the Har Ki Dun camp.
• Maninda Tal, if your itinerary includes it — a small high lake that adds about 700-1,000 ft to the trip's high point.

The ascent profile is reasonably gentle if the operator sleeps low at Kalkattiyadhar or Boslo and visits the valley as a day walk, which is the standard pattern and is also what the meadow camping rules force. Drink 3 to 4 litres a day; a genuinely clear urine output is the crude field measure. Avoid alcohol entirely and do not use sleeping tablets, which suppress the breathing drive at altitude. Report headache early rather than at dinner. The rule that saves lives is simple and non-negotiable: if symptoms are not improving, or if there is confusion, loss of balance, breathlessness at rest or a wet cough, descend immediately and at night if necessary, because descent is the treatment and everything else buys time. The operator should be carrying a pulse oximeter and taking readings twice daily, bottled oxygen with a working regulator and mask, a first aid kit with dexamethasone and nifedipine available to a trained guide, and a written evacuation plan naming the nearest road head and hospital. Ask to see the oxygen cylinder before you leave Sankri; ask what its pressure reads.

• The operator grades this Easy - Moderate; independent sources support Moderate. We list the sourced grade — see the sources below.
• Build for six to eight weeks before departure. A workable target is 5 km of running in 35 minutes, or a 45 minute brisk walk with 400 m of ascent, done comfortably three times a week. Add at least two sessions a week carrying a 6 to 8 kg pack on stairs or a hill, because the trek's difficulty is cumulative load-bearing descent, not cardiovascular peak. Anyone who cannot climb ten flights of stairs without stopping should postpone rather than book.
• This trek turns genuinely life-threatening in three ways. First, an ignored altitude illness: someone who presses on to Maninda Tal with a worsening headache and ataxia at 3,800 m, hours from any road, in a group with no oxygen. Second, a fall on old snow or wet stone on the exposed traverse above the Supin, where a slip is a long one and evacuation is on a stretcher carried by porters. Third, weather and road: a monsoon or heavy early-snow event that traps a group above Osla, or a landslide that closes the Purola-Mori road behind you. Deep winter adds hypothermia to the list, with reported night temperatures near -15 C and the real possibility that no rescue can reach you quickly.

Nearest railhead: Dehradun (DDN), approximately 190 to 200 km from Sankri by road, 8 to 11 hours via Mussoorie, Purola and Mori. Nearest airport: Jolly Grant, Dehradun (DED), approximately 210 to 225 km from Sankri, 9 to 11 hours by road. Basecamp: Sankri.

• 3 x quick-dry full-sleeve trekking t-shirts (full sleeve for sun at altitude, not just warmth)
• 2 x quick-dry trekking trousers, no denim, no cotton
• 1 x thermal base layer set, merino or synthetic, mid weight (about 200 gsm)
• 2 x fleece or synthetic mid layers, roughly 200 and 300 weight
• 1 x down or synthetic insulated jacket rated to about -10 C (550 to 650 fill down is ample for this altitude)
• 1 x waterproof and windproof shell jacket with a hood, taped seams
• 1 x waterproof overtrousers, needed for March snow and for June and September rain
• 1 x insulated hat or beanie that covers the ears, plus a sun cap or wide-brim hat
• 1 x neck gaiter or buff, and a second as a spare
• 2 x gloves: a thin liner glove for walking and a waterproof insulated outer for snow and camp
• 4 to 5 pairs of trekking socks (wool or wool blend), plus 1 thick pair kept dry for sleeping only
• Thermal leggings for camp and sleeping in October to April
• 1 x waterproof high-ankle trekking boots with a lugged sole, broken in over at least 50 km before the trek. Ankle support matters here because the mule track is uneven stone
• 1 x lightweight camp shoes or sandals with a closed toe
• Gaiters if there is snow above Osla, which is normal in March, April and November
• 50 to 60 litre backpack with a padded hip belt and a rain cover, if you carry your own load; 20 to 30 litre daypack if you offload to a mule
• Sleeping bag rated to a comfort (not extreme) temperature of about -10 C for March, April and November; most operators supply one, so confirm the rating rather than assuming
• Closed-cell foam or inflatable sleeping mat with an R-value of 3 or better if you are supplying your own
• 2 x trekking poles with snow baskets. On this trek they matter more on the descent than the ascent
• Headlamp with fresh batteries plus a spare set. Cold halves battery life
• Microspikes or instep crampons for March, April and late-season snow above Kalkattiyadhar. Confirm whether the operator supplies them
• 2 x 1 litre water bottles, at least one insulated or wide-mouth so it does not freeze shut overnight, or a 2 litre bladder plus one hard bottle
• Water purification: chlorine dioxide tablets or a filter. Stream water is generally clean high up but the trail passes inhabited villages and livestock
• UV400 sunglasses, category 3 or 4, wraparound. Snow glare above the tree line is severe
• Power bank of 10,000 mAh or more; there is no charging beyond Sankri
• Dry bags or heavy-duty bin liners to keep the sleeping bag and spare clothes dry
• Toilet paper and a small trowel or zip bags for carrying out waste, plus a bag for all your own litter
• Original government photo ID (Aadhaar, driving licence or passport) plus 2 photocopies for the forest check post
• 2 to 4 passport-size photographs, asked for at permit issue
• Foreign nationals: passport and valid Indian visa, plus copies. Expect a higher park fee and a separate register at the check post
• Medical fitness certificate and a signed self-declaration or indemnity, which most operators on this route require
• Travel or trekking insurance policy number and the insurer's emergency contact
• Emergency contact details written on paper, not only in a phone that will be dead by day three
• Blister kit: zinc oxide tape, a second-skin or hydrocolloid dressing, and a needle. Foot problems end more Har Ki Dun treks than altitude does
• Paracetamol for headache and fever; ibuprofen or diclofenac for muscular pain, taken with food
• Diamox (acetazolamide) is the standard altitude prophylaxis and treatment, but dosing, and whether you should take it at all, is a decision for a doctor who knows your history and your sulfa allergy status. Do not start it for the first time on the trail
• An anti-emetic such as ondansetron and an anti-diarrhoeal such as loperamide, plus oral rehydration salts
• Personal prescription medication in the original packaging, in double the quantity you expect to need, split between two bags
• Antiseptic cream, a crepe bandage, and a small roll of duct tape for repairs and for taping hot spots
• High-SPF sunscreen (50+) and SPF lip balm. Reapply; reflected UV off snow burns the underside of the nose and chin
• Personal hygiene items and, for women, enough sanitary supplies plus sealable bags to carry them out