Looks like Mount Davis.
Can't be too steep if a T can descend in top gear.
I wonder when this pic was taken. Looks like it says "CEG 19" in the right corner as in 1919. I would think it is later as it seems pointless to warn drivers of the world's most popular car to use second (high), gear. I agree it can't be that steep as there is a T climbing to the top. My car seems to have equal ability and limitations up or down hill.
Thought this might be of interest to the history buffs among us.