Simply put, this symbol shows an obstacle at
an elevation measured in MSL (Mean Sea Level). It is listed in MSL because the
pilot is more concerned with his Altimeter reading than converting to feet above
ground level (AGL), so MSL is given. The bigger dot inside a bigger wedge
indicates the Highest obstacle on the diagram.
Dots with NO wedge indicate measured ground
elevations at that particular spot given in Feet MSL.
Hi-Lighted is an obstacle 4,229 feet above
Mean Sea Level.