Start: 20th September 2027 | End: 28th September 2027 | Meeting location: Nan City, Thailand | Availability: 6 Spaces
Included in the tour:
- Expert English/Thai speaking guides.
- Transport.
- High Quality Accommodation.
- Food & Water.
- Permits/Entry Fees.
Introduction
Expedition Northern Thailand is our first Deluxe Collection exclusive, featuring 8 nights staying in a fantastic resort surrounded by luscious evergreen rainforest. This gives us time to properly explore the incredibly biodiverse mountains of Nan province, and maximise our chances to see the top showstopper species occurring here. We will spend every day and night out in the field, road cruising, stream walking and trail hiking in search of countless incredible species, making the most of different weather conditions and elevations. The quality of accommodation and catering is higher than all our other available group expeditions, with different set menus of delicious local/western food, as well as designated wood fire pizza night at a local restuarant. Once you arrive in this area, you will immediately understand why even 8 nights is not enough time.
Drone view of our resort.
View from the restaurant.
Montane forest trail.
Mid-elevation evergreen forest.
Hmong tribal village in the mountains.
Prime herping.
Another view of our resort.
Our accommodation is at 600 meters above sea level, but we will focus the majority of our search effort on upper elevations of the mountain (1,100 - 1,700 meters), where the majority of the showstopper snake species occur. Of the three 'holy grail' species on this mountain, two are restricted only to the highest elevations of the mountain. The Red River krait (Bungarus slowinskii) was first discovered in Thailand in 2018, and has since only been recorded from a few individuals - most of which were found by the Explore Herpetology team. While highly venomous, this species is very slow moving and reluctant to bite, usually found crossing roads or hunting in drainage ditches. We were very lucky to see large adults of this magnificent species on both our 2024 and 2025 editions of this expedition.
Unlike the Red River krait, the second 'holy grail' species from montane elevations is the fast-moving and diurnal black-striped green rat snake (Ptyas nigromarginata). This is arguably one of the most beautiful snakes in the world, with the unique clade occurring in Northern Thailand and Laos being the absolute best of them all. This regional form of the species can grow to over 3 meters in length, and has by far the most vibrant colouration in both juvenile and adult form. This species is extremely rare, but mid to late September provides the highest chances to encounter it, as juveniles emerge and the roads have significantly less daytime traffic than October.
The final species we consider to be part of the ultimate trinity of Nan province specialties is the bamboo false cobra (Pseudoxenodon bambusicola) - the only species our team has not personally found in the area (although we did photograph one found by a local friend). This snake is typically found below 1,300m, and is active both day and night alongside small mountain streams. It is surprisingly large and very thick-bodied, and comes in both a bluish-grey and yellow phenotype - capable of spreading a broad hood with a 'monocle' marking. It is primarily active from late November to February, but can also be found throughout the year.
Black-striped green rat snake (Ptyas nigromarginata) - adult
Black-striped green rat snake (Ptyas nigromarginata) - adult
Black-striped green rat snake (Ptyas nigromarginata) - juvenile
Red River krait (Bungarus slowinskii).
Red River krait (Bungarus slowinskii).
Red River krait (Bungarus slowinskii).
Bamboo false cobra (Pseudoxenodon bambusicola).
Including the Red River krait (Bungarus slowinskii), these mountains are home to a minimum of 10 venomous snake species. This includes four additional elapids and five species of pit viper. On our 2024, 2025 and 2026 herping trips to Northern Thailand, we were treated to an encounter with an adult northern king cobra (Ophiophagus hannah) while road cruising during the daytime. September is especially good for seeing juveniles of the brown-banded mountain cobra (Naja fuxi), while Wanghaoting's krait (Bungarus multicinctus wanghaotingi) and the brightly coloured annulated coral snake (Sinomicrurus annularis) are both active at night at mid to high elevations.
Those who enjoy green vipers are in luck, as there are three different species of "green bean" occurring at the different elevations of the mountain, which can often all be found within one night. Guo's pit viper (Trimeresurus albolabris guoi) is common in agricultural areas and forest edges below 1,200 meters, the Yunnan pit viper (Trimeresurus yunnanensis) is common at the very top of the mountain, and the Lanna pit viper (Trimeresurus lanna) is abundant in all forested areas up to around 1,500 meters. Certain nights with particularly good conditions and activity levels can produce very high numbers of these snakes.
Our favourite pit viper present in this area is the secretive mountain pit viper (Ovophis cf. monticola), which emerges after very heavy rains. We usually find this viper by flipping through decaying leaf litter or fallen logs, but sometimes it is found crossing the road. September is one of the best times of year to find the mountain pit viper. The Malayan pit viper also occurs in this area, at the lowest elevations on the west side of the mountain, but we rarely search for this species as this expedition focuses on finding the highland endemics present on the upper slopes and valleys.
Yunnan pit viper (Trimeresurus yunnanensis).
Guoi's pit viper (trimeresurus albolabris guoi).
Lanna pit viper (Trimeresurus lanna).
Mountain pit viper (Ovophis cf. monticola).
Wanghaoting's krait (Bungarus wanghaotingi).
Annulated coral snake (Sinomicrurus annularis).
Brown-banded mountain cobra (Naja fuxi).
Northern king cobra (Ophiophagus hannah).
If you enjoy more than just snakes, this expedition offers the chance to see some of the rarest amphibians and lizards present in Thailand. The best amphibian is the micro-endemic Phu Kha crocodile salamander (Tylototriton phukhaensis). To find this species, we will hike to 1,900 meters in elevation. Around the same pond as the salamander, we will also see the giant flying frog (Zhangixalus feae). We also have some consistent breeding ponds for Gordon's bug-eyed frog (Theloderma gordoni), an incredibly impressive "mossy frog". Other rare species such as the Zhushihe mountain toad (Orphryoprhyne pachyproctus), white-lipped flying frog (Zhangixalus pachyproctus) and white-backed bug-eyed frog (Theloderma albopunctatum) can also be reliably found at specific breeding sites.
Arguably rarer than any of the key target snakes, Harold Young's supple skink (Lygosoma haroldyoungi) is by far the most coveted lizard occurring in the area. This ridiculous skink can be as long as your forearm and as thin as your finger, with the most striking blue, orange and black banding. They can be found crossing the road (by day or night) or under leaf litter in mid to high elevation forest trails, but are extremely scarce. The Khakhien hills false-bloodsucker (Pseudocalotes khakienensis) is another beautiful and elusive lizard we can target on windy nights or basking on the road. In 2026, we encountered an impressed tortoise (Manouria impressa) in the forest, another of the most special non-snakes inhabiting the mountain.
Phu Kha crocodile salamandar (Tylototriton phukhaensis)
Giant flying frog (Zhangixalus feae)
Giant flying frog (Zhangixalus feae)
Gordon's bug-eyed frog (Theloderma gordoni).
White-backed bug-eyed frog (Theloderma albopunctatum).
Zhushihe mountain toad (Orphryophryne pachyproctus)
Harold Young's supple skink (Lygosoma haroldyoungi)
Impressed tortoise (Manouria impressa).
Khakhien hills false-bloodsucker (Pseudocalotes khakienensis).
Snakes galore
While we will try to find as many amphibians and lizards as possible, this expedition is really about the snakes. Northern Thailand has the highest daily average of snake encounters of any trip we offer, especially for daytime encounters. Less than 10 snakes per night would be considered poor activity, with our best nights often exceeding 20 snakes and upwards of 10 species. This location holds our all-time record of 19 species of snake in one single day. Our primary method of searching is road cruising, which typically results in a higher diversity of snakes than any other strategy, but every night is broken up with road walks (where we shine trees and drainage ditches), trail walks and stream hikes.
There are several common species which we expect to see most nights of the trip, and an even broader number of semi-common species which are sure to make at least one appearance across 8 nights, and then a myriad of rare species which will induce high levels of excitement if they are encountered. Some of the most notable species we have not featured above include the stunning Yunnan red bamboo ratsnake (Oreocryptophis pulchra), Yunnan beauty ratsnake (Elaphe taeniura yunannensis), Laotian bearded snake (Parafimbrios lao), many-banded green snake (Ptyas multicinctus), large-eyed false cobra (Pseudoxenodon macrops), but there are so many more snakes which may catch your eye or appear unexpectedly.
There are simply too many to possibly list, so in the photo grid below are a selection of species we have found and photographed in Nan province from 2019 - 2026. There are still several species of snake we have not yet seen in this area, so hopefully you can help us add something to this photo grid come September.
Yunnan red bamboo ratsnake (Oreocryptophis pulchra).
Yunnan red bamboo ratsnake (Oreocryptophis pulchra).
Large-eyed false cobra (Pseudoxenodon macrops).
Many-banded green snake (Ptyas multicinctus).
Yunnan beauty ratsnake (Elaphe taeniura yunnanensis).
Yunnan green cat snake (Boiga cf. cyanea).
Many-spotted cat snake (Boiga multomaculata)
Banded wolf snake (Lycodon fasciatus).
Gunther's smooth snake (Liopeltis frenata).
Radiated ratsnake (Coelognathus radiata)
Eberhardt's kukri snake (Oligodon eberhardti)
Small-banded kukri snake (Oligodon fasciolatus).
Yunnan slug snake (Pareas yunnanensis).
Fire-backed keelback (Hebius igneus).
Eastern keelback (Trimerodytes cf. percarinatus).
Khasi keelback (Hebius khasiensis).
Blue-eyed bamboo ratsnake (Gonyosoma coeruleum).
Laotian bearded snake (Parafimbrios lao).
Heller's red-necked keelback (Rhabdophis helleri).
Tam Dao kukri snake (Oligodon cinereus tamdaoensis).
Mountain slug snake (Pareas macularius)
Yunnan mountain keelback (Trimerodytes yunnanensis)
Joynson's kukri snake (Oligodon joynsoni).
Chapa wolf snake (Lycodon chapaensis)
Collared black-headed snake (Sibynophis collaris).
Vogel's bronzeback (Dendrelaphis vogeli).
Black-barred keelback (Rhabdophis nigrocinctus).
Spencer's stream snake (Opisthotropis spenceri)
Berdmore's slug snake (Pareas berdmorei).
Assamese mountain snake (Plagiopholis nuchalis)
White-spotted slug snake (Pareas margaritophorus).
More details:
The typical daily agenda on this expedition is breakfast at 10am, followed by road cruising and trail walking during the midday and late afternoon, with breaks for photography, coffee and rest. Dinner is served at 5pm as we must be out at sunset to make the most of prime time. At night, we will road cruise during peak activity hours, supplementing the evening activities with stream walking, roadside shining and hiking on trails. Activity tends to slow down after 11pm, so we typically finish herping by midnight. We will be split into two or three separate groups on most days, and will share our best finds together. Covering as much ground as possible is essential for finding the most desirable species in this region.
Phu Kha bent-toed gecko (Cyrtodactylus phukhaensis).
Striped sticky frog (Kalophrynus interlineatus).
Scale-bellied horned dragon (Acanthosaura lepidogaster).
Yunnan bush frog (Gracixalus yunnanensis).
Rosy litter frog (Leptobrachella eos).
White-lipped horned frog (Megophrys major).
Pseudocalotes microlepis.
Thai stream skink (Tropidophorus thai).
Leptobrachium huashen.
Accommodation:
We will be staying at Bo Kluea View for the entirety of our stay, overlooking the river and forested hills with the opportunity for herping right outside our private bungalows. The beds and facilities are high-quality, with WiFi and 5G available throughout the property. The standard package for this expedition is a shared twin-bed bungalow, but we offer a single supplement package for those who want a private room, or deluxe bungalows with increasing levels of luxury for those who really want to upgrade their stay.
Food:
We will eat both breakfast and dinner at the restaurant at our resort, with one visit to a pizza restaurant later in the trip. The food at the resort is a set menu with a specific theme for each night, so let us know if you have any dietary restrictions. Food is plentiful and diverse on each night regardless of the theme. There is a 7-Eleven within walking distance of the resort, where we can stock up on snacks for while we are in the field.
Environmental conditions & fitness:
On sunny days, the temperature in the lower elevations can rise to around 28°C with high humidity. However, at the higher elevations of the mountain, the temperature can drop as low as 14°C at night. We highly recommend packing at least one sweater. This trip is scheduled during the latter rainy season in Northern Thailand, so you must bring waterproof clothing.
The majority of herping during this trip is road cruising and road walks, which is generally very relaxing and accessible for everyone. However, we will host more challenging hikes for those who want to partake, including along streams and hikes to easily accessible mountain summits. Mosquitos, leeches and other biting/stinging animals are part of jungle life, so long trousers/pants, long sleeved shirts and long socks are strongly advised. We specifically recommend rubber boots and hiking boots as both will come in handy on this expedition.
Travel information:
All participants must arrive at the designated meeting point in Nan City by midday (12:00pm) on the 20th September 2027. We advise all guests to arrive the night before and get a good night’s sleep before the expedition begins, but morning flights from Bangkok are available on the 20th. Daily flights to/from Nan Nakhon Airport are available from Bangkok, but we recommend booking as far in advance as possible. We will drop everyone off at the airport in Nan City on the 28th September by midday (12:00pm), but can send one car earlier if people want to take an earlier flight.
It is the guests’ responsibility to meet all entry requirements needed to enter Thailand, including visa procedures. Explore Herpetology can help advise entry requirements. Guests from the UK, US, EU, Australia and many other countries can enter Thailand visa-free for up to 30 days. Make sure to check the entry requirements for your country before booking. There are no mandatory vaccinations or COVID restrictions in place for travellers entering Thailand or joining our expeditions. All visitors to Thailand must complete the Thailand Digital Arrival Card within 3 days of travel. Do not use any third party websites which require you to pay for this service. Contact the Explore Herpetology team if you want the authentic link.
