This is a challenging route that climbs up to Col de la Biche and then traverses to Grand Colombier primarily on gravel or trails.
Starting beside the Rhône river, I would climb the first few paved kilometres of the super-steep east side of Col de la Biche, but turned onto a gravel “road” more than 10 kms from its summit.
It’s a decent gravel road but at times very difficult with all the sliding little stones on such a steep climb. I loved the solitude. I guarantee you won’t see a soul on this stretch.
See here and here for details of the paved routes up Col de la Biche. See here for a post with video of the beautiful paved “Lacets” side of Grand Colombier which will be the mountain-top-finish in stage 15 of the 2020 Tour de France.
As I reached the top ridge of the massif, I wasn’t too far from Col de la Biche. But my route turned onto a terrible rocky track. I’d just passed a very old mountain bike route sign, so I ignored the crazy surface and took the mountain bike trail. I soon reached the paved road perhaps 2 kms from Col de la Biche. Before visiting the col I made a quick there-back detour in the opposite direction for the first good Alps view of the day:


This route is entirely in the Jura mountains, but on a clear day the Alpe views are great:

The final two kilometres to Biche are down then up. I of course visited the Col, but immediately turned around. Briefly descending then joining a fantastic gravel road that would take me all the way to the summit of Grand Colombier.
In the photo below, I am at just below 1300 metres and the high point in the distance is Grand Colombier.
Much of this stretch is in the woods. A brief few hundred yards are ultra steep, and I needed to push – but it’s generally a great road/trail. If you zoom the map, you’ll see I made a tiny detour to visit Col de Charbemènes at 1317m. Here’s an old post where I cycled to this col on an unpaved route from the far side of the massif.


Finally, I would join the paved road exactly one kilometre below the summit of Grand Colombier on its west side. In the photo below, you can see bottom-right where my gravel route joins this crazy steep paved stretch.

Again, brilliant views from the summit of Grand Colombier (1501m)
See here for details of all four paved sides of Grand Colombier.
Below, great view of Lac du Bourget (largest and deepest lake entirely in France), and Tour de France road paint in anticipation of Stage 15 of the 2020 Tour de France – which will climb Grand Colombier from the Culoz side.
I had mapped an unpaved descent of Grand Colombier, but I had my gravel bike not my mountain bike and I decided extra-steep downhill gravel was a lousy idea. So I just took the steep, paved descent to Anglefort and finally a quick traverse back to the start.
This was a fun, quiet, challenging ride – off the beaten track. For those looking to visit the famous paved side from Culoz, note that there are several bike-only days every year where the route is kept car-free for several hours. And the last one of 2020 is this Saturday! Details on the sign:


A 3D video of the ride: