Their base is at 1450 meters (GPS lat/long = N45.32540 E6.04721) on the West side of the Belledonne mountain group a bit north of Grenoble - (I think 1450m is significantly higher than any groomed XC ski trail in the Jura.) Most of their trails are much higher than the base - around 1600-1900 meters.
Great views of dramatic mountains in many directions from the higher trails (way more spectacular than places in the Jura I've tried).
Shortcoming was that a significant portion of their trail distance was not recently groomed - (as their website reported) - but enough for me to have plenty of fun skiing (skating style).
Most of the trails were rather hilly -- except perhaps "les Ramiettes" trail (long out-and-back) which I didn't try.
The combination of "le Crete Luisard" and "les Cretes" was one of the most spectacular groomed XC ski trails I've ever been on -- runs along a ridge with big views of dramatic peaks + ridges in all directions. Also has in interesting design with variations in the ups + downs + curves -- goes up to almost 1900 meters (near to summit of le Grand Rocher) -- with some serious steep sections.
Biggest reservation: Reaching most of the trails (except "les Ramiettes") requires first going up the "acces refuge" trail which is a long non-gentle climb, fairly sustained for about 275 vertical meters (900 ft) over 4 km distance (? which would be an average steepness grade of 7% ?). And unlike the other hilly trails it had that typical Euro semi-boring design.
A deterrent especially for skaters (at least those at less than regionally competitive level). Fortunately snow conditions were firm for me skating up, but even so I made sure to stop and rest several times, save my strength for the fun trails higher up. Great trail for a hill workout (I can see how one of the biathlon medalists in the Vancouver 2010 Olympics came out of le Barioz).
- (? Maybe there's some time when they give skiers a ride up on the grooming snowcat ? - just a suggestion)