Here is a map Panzer Dragoon world:
Now look at the area where the valley and Excavation site are. Wasn’t the Deep Canyon Gluch area further north than the Excavation site? According to this map it is further south which doesn’t make sense to me. However it would make sense if you considered the flow of the river - in the canyon level Lagi flies against the current; according to the direction of the arrow he would be doing just that.