From the beginning of Atabakan e- Lor, the Bakhtiari tribe, have been always living in a nomadic way in the great Lor territory and have connected their summer settlements to their winter habitats  via building roads and bridges in mountainous far-fetched areas. The Chaharlang ilrah is one of the most longest of these roads that the most impassable route of which begins in Sarkul in Miankoh e-Aligoudarz  and ends to Salend mountain after crossing the Kul bridge on Bakhtiari river. The authors' field research revealed that there are traces of an old road with several bridge openings in all impassable parts of the distance between Sarkul and Kul bridge, constructed as a paved road via carving rocks and with materials such as stone and saroj. There is an inscription on a large stone at the Aligoudarz beginning of  the road which is carefully read and decoded for the first time by authors. This stone inscription stated that the construction of this road was completed by Yusef Khan Bakhtiari one of the local rulers of the Bakhtiari tribe, in the year 1680 AD.. There are also signs of a large historical fortress and its ramparts known as Khalil-Khan Castle at the Sarkul beginning of the road. The present article attempts to introduce the inscription and  structures along the route and their relation to the Bakhtiari rulers of Safavid era.