I am asked this about every three weeks, and almost always in the same way. People ask whether the dog can come, adding straight away that it is friendly, never wanders off, and can be kept on a lead if really necessary.

I understand where they are coming from. That is also why the answer comes as a surprise.

In the nature reserve, the answer is no, even on a lead

The Haute Chaîne du Jura National Nature Reserve covers the ridge above us, from the Crêt de la Neige to the Croix du Reculet and well beyond. Its regulations are explicit: “Dogs are prohibited, even when kept on a lead”.

There are only four exceptions. Sheepdogs herding or guarding a flock. Rescue dogs. Hunting dogs, during the hunting season only. And sled dogs, under a traffic plan of their own.

So the lead changes nothing. This is not a rule about behaviour, it is a rule about presence.

Many people find out when they reach the start of the trail, and turn back. It is a shame, because there are some lovely walks to do with a dog twenty minutes away. I come back to that below.

Why such a strict rule

Because a dog, however well behaved, however close to you, is not seen as a walker by the animals that live there.

Winter makes this far more serious than you might think. A chamois uses about six times more energy walking through fifty centimetres of snow than on dry ground. If it has to flee in those conditions, it is ten times. Add a bit of slope and it reaches sixty times. These orders of magnitude come from a study by Mattfeld, Geist and Moen, used in training material on winter wildlife disturbance.

The roe deer is even more vulnerable. Twenty kilos, slender legs, no adaptation to moving on snow. It sinks, it tires, and it is in March that animals are found attacked by a fox that would normally be quite unable to catch one.

The point I find most telling is this one. A dog moves over snow better than any hoofed animal in our mountains. A chase, even an unintended one, even over two hundred metres, is completely one-sided.

And fleeing is not the only sign. An animal watching you without moving is already on alert. It will not start feeding again straight away, and at that time of year every hour without food comes out of reserves that do not build back up. I say more about the species concerned in my article on the wildlife and plants of the Haute Chaîne du Jura.

And the high-altitude forests further north

If you head north through the range, into the Jura department, a biotope protection order revised in 2019 protects five sectors of high-altitude forest, the habitat of the capercaillie: the Massacre, the Bois de Ban-Arobiers, the Risoux, the Haute-Joux and the Combe Noire.

From 15 December to 30 June, entry is prohibited outside authorised routes, mapped forest by forest, and bringing dogs in is strictly forbidden. From 1 July to 14 December, they must be kept on a lead or harnessed. Separate orders cover other sectors in the Doubs and the Ain.

These are two separate sets of rules, on two separate territories, which reach the same conclusion for the same reason.

Across the border, at La Dôle

La Dôle is in Switzerland, in the canton of Vaud, and lies within a federal game reserve. The rules there are different, but no more permissive.

In the federal game reserves of Vaud, dogs must be kept on a lead all year round, with exceptions for working dogs used by the police, rescue services, herding and livestock protection. And when there is snow, only waymarked paths may be used. The legal bases are the federal ordinance on federal game reserves of 30 September 1991 and the cantonal wildlife law.

In other words, your dog can go up La Dôle on a lead, but you may not leave the waymarked route as soon as there is snow.

Elsewhere in the Pays de Gex: what French law says

Outside protected areas, walking with your dog remains free, under three conditions that few people know precisely.

A lead is compulsory in woods and forests from 15 April to 30 June, away from forest tracks. This is the order of 16 March 1955, issued to protect nesting birds in spring. A forest track is understood broadly, a road, path or trail, including a long-distance GR route, but a firebreak or a plot boundary is not one.

The rest of the year, the dog must stay under direct control. Rural law considers a dog to be straying as soon as it is no longer under its owner’s effective supervision, is out of earshot, or moves more than a hundred metres away. A hundred metres is not much on an open alpine pasture.

And if the dog goes after game, even far from you, the owner is answerable for the offence.

So where can you walk with your dog around Gex?

The good news is that the protected area is the ridge, not the whole Pays de Gex.

The foothill forests, the farm tracks between Gex and Divonne, the lakeside, the low-altitude paths on the plain: all of these remain open, provided you respect the spring lead rule and keep your dog close when there are herds about.

The simple rule I give people who ask: the higher you go, the more regulated it is. Down below, it is a matter of common sense and season. Up top, it is an outright ban.

And on my outings

Let me say it clearly, because the question always comes up at the end: I do not accept dogs on WhyTrek outings, whether group or private.

It is not a matter of principle. I am happy to meet dogs the rest of the time. It is that most of my routes pass through the reserve or along its edge, where the rule does not depend on me. And on the others, a group walking together for four hours with a dog that knows nobody changes the pace, rearranges everyone’s places and takes attention I prefer to keep for the group.

I would rather say so when you book than in the car park.

How to check before you go

The boundaries of the nature reserve are not always marked at the start of the trails, and the same route can go in and out of the protected area.

The most reliable way is to look at the official maps on Géoportail, which shows protected areas, or to read the page listing what is prohibited in the reserve (in French) before choosing your route. If in doubt about a specific outing, you can also write to me and I will look at it with you.

And if you are looking for a guided outing on the Haute Chaîne, they are all on the Day hikes page.

Want to check what you have learnt?

Dogs are just one chapter of the rules that apply as soon as you walk in the countryside. What the law says when you hike covers the subject in thirty-two questions, from leads in the forest to lighting fires two hundred metres from woodland. On what our presence really costs animals, what crossing your path costs a chamois gives the figures. And if wildlife is what interests you, the quiz on Jura wildlife in winter explains what these rules protect.

Can you take your dog hiking in the Haute Chaîne du Jura?