The stairs are easiest to spot in the morning or evening when they're shadowed. To the right and above the tower is the upper, big set of stairs with a tunnel mouth at the top. Further right and lower down is the other set of stairs and another tunnel mouth at the top of them. Directly above the upper set is the top of the Fire Control Station. That upper tunnel is actually more like a hall which leads to a set of spiral stairs that will take you up two stories to the top level and an exit to the last short section of trail.
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