Putting Margaret Lamb's analysis of four mountain pass accidents together with what Cary has posted about flying high mountain passes, I have learned a lot. Because I have always flown pretty low powered and high time engines at all heat, wind, and time of day conditions without O2, I have experienced little true high altitude flying for more than a few minutes.

Although not putting the terrain on and always flying in a drainage, I can see that both Margaret and Cary were always aware of where the drainage was and always kept enough energy in potential gravity trust of altitude to use said drainage to escape even a severe downdraft.

Other than time, energy management, and fuel use, the big advantage of orograraphic or hydraulic valley ridge system flying is that we are always up close and personal with the valley ridge to pass system. There is never the expectation that we will continue all the way to the flat meandering stream on the pass above the tree line where we could use the energy of low ground effect if need be. Because we are unsure,we are greedy of both lateral and vertical space.