Very nice 2.5 hour walk with views of the Alps and VallÃ©e de l’EstÃ©ron. A bit long, 1.5 hours, to get Amirat (actually 500 meters before) and the roads are pretty twisty, but it is worth it.
Less than two hours of walking 6.8km with 350m up/down. The start is the main up.
The RandOxygene guide is here and is correct. Yellow markers are pretty consistent.