Sources

• Distances, the line of the road and fuel pumps: © OpenStreetMap contributors, Open Database Licence. Routes worked out with the Open Source Routing Machine.
• Heights: NASA Shuttle Radar Topography Mission, public domain, served by Open Topo Data.
• Nathu La

  en.wikipedia.org · Encyclopedia

• Zuluk Travel Guide 2026 | Silk Route Sikkim

  discoverwithdheeraj.com · Published guide · dated 26 August 2026

• Tourism and Civil Aviation Department: general information

  sikkim.gov.in · Official page

• The NEW Sikkim Permit (2026): Step-by-Step Guide

  bestofnortheast.com · Published guide · dated 3 April 2026

• Sikkim may bar two-wheelers from RAP, PAP areas under proposed permit norms

  indiatodayne.in · News report · dated 19 August 2026

• Heavy Snowfall in Sikkim: Tourist Permits Suspended, Road, Nathula and Tsomgo Lake Closed

  nativeplanet.com · News report · dated 10 January 2025

• Sikkim government to start issuing tourist permits for Tsomgo Lake and Nathula Pass

  indiatodayne.in · News report · dated 13 October 2023

• Sikkim Bike Permit Rules: What Every Rider Needs to Know Before Hitting North Sikkim in 2026

  northeastindiaconnect.com · Published guide · dated 27 August 2026

• How to self drive a motorbike or car in Sikkim

  darjeeling-tourism.com · Published guide

• NH-10 reopens after six days of landslide disruption in Sikkim and Kalimpong

  newsonair.gov.in · News report · dated 17 August 2025

• Sikkim begins statewide road inspections to assess monsoon damage

  indiatodayne.in · News report · dated 21 September 2026

A gap is not a fact. It means we looked and found no source.

• No report found of a Cabinet decision on the 19 August 2026 two-wheeler proposal: one web search and the Sikkim front pages of two news sites were checked on 28 September 2026.
• Open days for Nathu La conflict: the official page says Tuesday to Sunday; Wikipedia says Thursday to Sunday; a travel site says Wednesday to Sunday.
• No official statement found on whether a private motorcycle may ride the Zuluk route; two unofficial sources contradict each other.
• No dated winter closure and reopening dates found for Nathu La for 2024 or 2026.
• Highway number for the Zuluk to Rongli side not sourced.
• No official source for the 150cc minimum or the documents list.
• The vehicle pass portal vehiclepass.sikkim.gov.in could not be opened (certificate error).
• Fee amounts are not on the official page and are left out.
• Videos not collected.
• Some stretch distances are doubtful. The open map may not know the road riders use, so the routing service went the long way round.