I think the airstrip is in a national park - although not sure it is in Kenya.
O/T. I didn't rate Treetops when I stayed there in the 1980s, it just seemed like it was trading on it's name. If I remember correctly it wasn't in the treetops when I visited as they had all been cut down, although looking on GE now, looks like the walk in to the hotel has been re forested. However, it also looks like the location is a bit out on a limb, with settlements only 1km away to the N, E & S. I visited the Ark (also in the Aberdares) the previous year, and I remember that being in the middle of the forest, with just the water hole as the open space.