Normally I'm not scared of heights, but Sullivan's Knob at Bighorn Canyon was not a place I could stay for very long. It is surrounded on 3 sides by a drop of 500+ feet down to the Bighorn River. It wouldn't have been as bad if it wasn't so windy. I didn't want to set up my tripod because it might have blown over. There were several of these tough little trees growing right on the edge of the precipitous cliff, bending in the wind.