In reply to KlaasW:
You are spoilt for choice if you don’t go for the very high summits. Taking equipment is over the top unless climbing and not running is your main objective.
The highest summit I ran was Mont Buet, 3000m meters is probably about the limit in this region without equipment.
There are lots of trails on the south side of the valley on the Aiguilles Rouges, you can even get on to the ridges/ summits with some rock scrambing above Lac Blanc. It is very dependant on the amount of snow when you go though. Amazing view across to the Mont Blanc etc
I did not use axe or crampons, I just picked up a longish shaped stone for a little security on any steep snow crossings.
Other good runs with no snow are from the Midi middle station and across to montenvers.