The Humla Karnali is the upper reach of the Karnali, rising near the Tibetan border in the far north of Humla and running south and west through the district. Every road, trail and settlement in Humla is arranged around it. It is a gorge river for most of its length here, blue-green in dry weather and heavy brown in monsoon.
Where the Humla Karnali begins
The headwaters are over the frontier on the Tibetan plateau, and the river enters Nepal in the border country in the far north of the district, behind Hilsa, already running fast in a defined bed. At Hilsa, at about 3,720 m, it is a clear emerald green and narrow enough to be crossed by a suspension footbridge. That is the same water that reaches the Tarai days later as a very different river.
What the whole Karnali system does downstream, through the middle hills and out to Bardiya, is covered in the complete Karnali river guide. This page is the Humla reach only, from the border to where the district ends.
For the place of the Karnali among the major river systems of Nepal, the guide to the Koshi, Gandaki and Karnali sets out the wider structure.
The gorge, and why the road is where it is
Through most of Humla the river runs in a gorge rather than a valley. The walls are steep, often vertical, and the flat ground is measured in metres rather than fields. This is the single fact that explains the shape of the district: there is one line through it, the river cut, and everything human is squeezed onto it or perched above it.
The road takes the only line available, which means it is cut into cliff for long stretches with the river directly below and rock directly above. In several places waterfalls come off the wall and run straight across the track rather than under it. Rockfall is a continuous condition rather than an event. The corridor guide describes that road stage by stage.
Where the gorge opens even slightly, there is a village. That relationship holds all the way up the district, and it is why the settlements sit where they do rather than anywhere more convenient.
The confluences
Side streams, called khola, come into the Humla Karnali from both walls, and the confluences are the landmarks of the district. They are where bridges go, where trails meet and, in the Hindu tradition of the Karnali basin, where temples stand.
| Point on the river | Approximate elevation | What is there |
|---|---|---|
| Hilsa | 3,720 m | The border. Emerald water, suspension footbridge, customs buildings |
| Simikot | about 2,910 m | The town is on a ridge above the river, not on its bank |
| Kharpunath | about 2,100 m | The Chuwa Khola confluence, the Bailey bridge and a Shiva temple |
| Srinagar, Adanchuli | about 1,650 m | Perched above the gorge on terraced slopes |
| Sarkegad | about 1,500 m | Valley floor. The river is wide and brown here rather than penned in |
The Chuwa Khola confluence at Kharpunath is the most consequential of them. The chasm there is what kept Simikot cut off from the national road network until 2025, and it now carries the bridge that closed the gap. The Kharpunath bridge post covers what that changed.
The colour of the water, and what changes it
In settled weather the Humla Karnali runs blue-green, strongest near the border and progressively less so downstream as more sediment joins it. The colour comes from glacial input and from the fact that the upper catchment sits behind the Himalayan crest, in dry country that sheds far less mud into the water than the monsoon-facing hills do.
In monsoon that changes completely. In monsoon 2026 the river below Kharpunath was opaque brown, running high and loud enough to be heard from the track well above it, and carrying wood. Side streams that are ankle-deep trickles in autumn were moving stones. Anyone whose picture of the Karnali comes from dry-season photographs will not recognise it.
The transition is not gradual either. A day of heavy rain in the catchment changes the river within hours, and it stays changed for days after the rain stops.
Crossing the river
Every crossing in Humla is a bridge, and the bridges are of three kinds. Suspension footbridges carry people and animals and are the oldest arrangement on the river. Vehicle bridges are few, and each one matters. Then there are the temporary crossings that appear and disappear on side streams as they are washed out and rebuilt.
Nowhere in the Humla reach is the river fordable by a vehicle in any season worth attempting. It is fast, cold and boulder-floored, and the depth is unreadable from the bank. The side streams are a different matter and are forded routinely, which is where the risk actually sits: a khola that looks trivial can be moving enough water to take a bike off its wheels.
The guide to suspension bridges in Nepal covers how that network is built and maintained across the hill districts.
Is the Humla Karnali rafted or fished?
Commercial rafting on the Karnali happens far downstream, on the sections below the middle hills, and the Humla reach is not part of that. The gradient is steep, access is measured in days, and there is no evacuation option, so it does not appear on any commercial programme.
Fishing is local and small-scale rather than a visitor activity. The high, cold, fast water of the upper reach is not productive in the way the lower river is, and food in the northern villages comes from barley, buckwheat, potatoes and livestock rather than from the river.
What the river gives Humla instead is power. There is no grid connection in the district, and electricity comes from local mini-hydro schemes on side streams along with solar. Those schemes are small, sit on the khola rather than the main river, and go down when a stream floods.
Following the river through the district
Travelling in Humla means travelling with this river, and the direction tells you what to expect. Going north and up, the gorge tightens, the vegetation thins from subtropical growth to pine to juniper to nothing, and the water clears. Going south and down, the opposite happens in the same order.
The northern section from Simikot toward the border is described in the Simikot to Hilsa road guide, and the terraced farming that occupies every workable slope above the water is covered in the guide to terraced fields. For the district as a whole, the Humla district guide puts the river in context.
The Humla Karnali through the year
The river is a different object in each season, and knowing which one you are looking at explains most of what you see.
In winter it is at its lowest and clearest, running cold and green in a wide stony bed with the high catchment locked up as snow. In spring, melt begins and the volume rises steadily rather than suddenly, which is the least dramatic phase and the one with the best combination of water and access.
Monsoon transforms it. Volume multiplies, the colour goes to opaque brown, and the noise is the thing nobody expects: a river of this size in flood is audible from a track hundreds of metres above it, continuously, for days. Every side stream contributes and the main channel widens into ground that is dry for the rest of the year.
Autumn is the recovery. The water drops and clears through October, the bed re-emerges, and the river settles into the version that appears in most photographs. That is also when the corridor beside it is at its most usable.
What grows along the river
The vegetation reads as a straight line up the district, and the river is the axis it is arranged on. On the valley floor around 1,500 m the growth is subtropical, hot and humid in summer, with rice in the workable ground. Climbing, that gives way to dry pine on the slopes, then to the barley, buckwheat and potato country of the middle villages, terraced onto every slope that will hold soil.
Higher again the trees thin to juniper and the cultivated ground runs out. Above that there is grazing and then nothing. The whole sequence happens over a couple of days of travel, which is a compression you do not get anywhere with gentler terrain.
The guide to terraced fields covers how that cultivated belt is built and worked, and it is the most visible human mark on the whole river corridor.
Travelling beside the river safely
The river itself is rarely the direct hazard. What hurts people is the ground above it and the streams running into it.
On the cliff sections the risk is rockfall from the slope above rather than the drop below, and the correct habit is to look up before stopping and not to rest anywhere with a fresh fan of rubble across the track. On the valley floor the risk is the alignment: the river takes bites out of the road every wet season and the missing sections are not always signed by anything.
And at every side stream the rule is to judge force rather than depth, and to wait rather than cross when the water is moving stone. Streams here rise and drop fast, so waiting is usually measured in hours. The monsoon conditions post covers what that season does to all of it.
What the river is called, and where the names change
The naming trips people up because the same water carries different names along its length. In Humla it is the Humla Karnali, which distinguishes this headwater branch from the other streams that join the system further down. Below the district it is simply the Karnali, and once it crosses into India it is known as the Ghaghara.
Side streams are khola, which is the ordinary Nepali word for a stream or small river and appears in dozens of place names across the district. Chuwa Khola at Kharpunath is the one that matters most to anybody travelling, because of the bridge that crosses it.
Where the names get genuinely confusing is with lakes and passes, which frequently carry both a Nepali and a Tibetan-influenced form in upper Humla. That is a feature of a district where the language shifts as you climb, and it is worth expecting rather than resolving. If a name looks like two names, it usually is.
Before you travel. Humla is a restricted border district and conditions change without notice. Roads close, flights are cancelled, permit rules and fees are revised, and the Hilsa crossing opens and shuts to different categories of traveller. Confirm the current position with the District Administration Office in Simikot, the Department of Immigration, or a registered local operator before you commit to a route.
Frequently Asked Questions
Where does the Humla Karnali start?
Its headwaters are over the frontier on the plateau. It enters Nepal in the border country in the far north of the district, behind Hilsa, already established as a fast river, and runs south and west through Humla as the upper reach of the Karnali.
Why is the water blue-green near the border and brown lower down?
The upper catchment sits behind the Himalayan crest in dry country that sheds little sediment, so the water starts clear with a glacial tint. Sediment joins it from every side stream on the way down, and in monsoon the whole river runs opaque brown within hours of heavy rain.
Can you cross the Humla Karnali without a bridge?
No. It is fast, cold and boulder-floored throughout the district and is not fordable in any season. Every crossing is a bridge. The side streams are forded routinely, and those are where the real risk sits in wet weather.
Is there rafting on the Humla Karnali?
Not commercially. Rafting on the Karnali system happens far downstream. The Humla reach is steep, days from any road head at most points, and has no evacuation option, so it does not appear on commercial programmes.
What is the Chuwa Khola?
A side stream that joins the Humla Karnali at Kharpunath at about 2,100 m. The confluence sits between vertical cliffs and was the last gap in the road up from Surkhet until a steel Bailey bridge was completed there in July 2025.
Does the river supply electricity in Humla?
Indirectly. There is no grid connection in the district and power comes from small mini-hydro schemes on side streams, alongside solar. Those schemes are vulnerable to flooding on the khola they sit on.
How does the river shape where people live?
Almost entirely. Humla is a gorge district with very little flat ground, so settlements occupy the few places where the walls step back, and everything else is terraced onto slopes above the water. The road takes the only line the river cut allows.