North Sikkim permits and altitude: what you need to know

Indian travellers need a permit for the restricted areas of North Sikkim: Lachung, Yumthang and Zero Point on one side, and Lachen, Thangu and Gurudongmar Lake on the other. Your operator applies, usually the day before departure, and the permit lists every traveller and the vehicle.

The permit is checked at police and army checkposts along the North Sikkim highway, typically around Mangan, Chungthang and, for Gurudongmar, beyond Thangu. Your driver handles the stops, but you must have your original ID with you, matching the details on the permit.

There is usually a small government fee built into the package price. Gurudongmar access may need a separate clearance or endorsement, which your operator arranges alongside the main permit. Zero Point is charged as an extra vehicle trip rather than a separate permit, but it also depends on the day's army instructions.

• Original government photo ID: Aadhaar, passport, voter ID or driving licence. PAN cards are often not accepted.
• Two to four recent passport-size photographs per person.
• Photocopies of the ID for each traveller; children need ID too, such as a birth certificate or Aadhaar.
• Names, ages and genders of everyone in the group, matching the IDs exactly.

Foreign nationals need two documents. The first is the Sikkim Inner Line Permit, which allows entry to the state and is issued at the Rangpo and Melli checkposts, at some Indian missions and tourism offices, or online. The second is a Protected Area Permit for North Sikkim, issued in Gangtok through a registered travel agent.

The Protected Area Permit for North Sikkim is normally given only to groups of two or more travelling with a registered agent. It covers Lachung, Yumthang and Lachen, but foreigners may not visit Gurudongmar Lake, Zero Point or other areas close to the border. Solo foreign travellers may find it hard to obtain unless the agent can group them with others.

Allow at least one working day in Gangtok for the Protected Area Permit. Bring your passport, Indian visa and several passport photos. Overseas Citizens of India and people of Indian origin with foreign passports should check their own status with the agent, as treatment has varied. Check current status before you travel.

Dzongu is a protected Lepcha reserve, and outsiders need a permit to enter, separate from the Lachung and Lachen permit. For Indian travellers it is usually issued by the district administration on the basis of an application your homestay makes, using copies of your ID. Send these at least a week ahead.

Foreign nationals need the Inner Line Permit and a Protected Area Permit that includes Dzongu, arranged through a registered agent, plus whatever local entry paperwork the district requires. Your homestay host and agent can coordinate. The process is less standardised than for Lachung, so start early. Check current status before you travel.

North Sikkim covers a huge range of height in a short distance. Dzongu and Mangan are below 2,000 m, Lachung and Lachen are around 2,700 m, Yumthang is about 3,564 m, and the highest points tourists reach are Zero Point at about 4,700 m and Gurudongmar at about 5,430 m. The table shows where you sleep and where you only visit.

The rule that matters most is to sleep low and visit high. You never sleep above about 2,750 m on a normal trip, which keeps the risk low. The danger comes from climbing 2,000–2,700 m in a single morning to Zero Point or Gurudongmar. Short stays at the top and a quick return lower are what keep most visitors safe.

Acute mountain sickness can affect anyone above about 2,500 m, regardless of fitness. It is common in a mild form at Zero Point and Gurudongmar. Most people feel a headache, a little breathlessness or tiredness, which passes when they come down. A small number develop more serious problems, and these need quick action.

Help your body by drinking enough water, eating light meals with carbohydrates, avoiding alcohol and sleeping pills, and moving slowly at height. A second night in Lachen before Gurudongmar is the single best step if your schedule allows. Some doctors prescribe acetazolamide for high-altitude travel; take it only on medical advice.

Children, pregnant women, older travellers and anyone with heart disease, lung disease, high blood pressure or anaemia should talk to a doctor before going above 4,000 m. Babies and young children are generally not taken to Gurudongmar. There is no shame in staying in Lachen or at Yumthang while others go higher.

• Mild signs: headache, nausea, poor appetite, dizziness, unusual tiredness.
• Danger signs: worsening headache despite rest, vomiting, confusion, stumbling, breathlessness at rest, a wet cough.
• What to do: stop going up; with danger signs, go down at once and seek medical help at Chungthang, Mangan or Gangtok.
• Oxygen cans give short relief, but descent is the real treatment.

On 4 October 2023, a glacial lake outburst from South Lhonak Lake sent a flood down the Teesta. It damaged the dam at Chungthang, washed away bridges and cut long stretches of the North Sikkim highway. Tourism in North Sikkim was suspended for long periods while roads were rebuilt, and different parts of the district reopened at different times.

Since then, monsoon landslides have continued to cause closures, and the authorities suspend permits when roads are unsafe. Repairs mean some stretches run on temporary alignments or one-way timings. None of this should stop you visiting, but it does mean you should plan flexibly.

Ask your operator about road status when you book, a week before you travel, and the day before departure. Keep a spare day before any flight or train. Read the cancellation policy, and buy travel insurance that covers trip disruption if you are travelling between June and September. Check current status before you travel.