Garmin GPS 175 Pilot's Manual page 208

Hazard Awareness
POWER LINE OBSTACLES
OBSTACLE
OBSTACLE GROUPS
An asterisk indicates when the obstacle database contains only a single
latitude and longitude for a group of obstacles. This occurrence is rare.
5-38
POWER LINE OBSTACLE LOCATION
Red power line is above or within 100 ft below current
altitude.
Yellow power line is between 100 ft and 1,000 ft below
current altitude.
White power line is between 1,000 ft and 2,000 ft below
current altitude.
GPS 175/GNX 375 Pilot's Guide 190-02207-02 Rev. B