Course Number - Unique ID identifying each course.
Map - If an online map is available, a clickable link "map" will appear.
Distance - Course distance in kilometers (km) or miles (mi). Marathons and half-marathons are listed with their exact metric definitions: 42.195 km and 21.0975 km respectively.
Type - The type of course: "road", "track", or "calibration".
Record-Eligible - Indicates whether records may be set on the course. This depends on drop and separation--see below. Also, records may be set only if the course has Active ("A") certification status and if the race is sanctioned.
Drop - Net elevation decrease from start to finish expressed as a fraction of the race distance in meters per kilometer (negative values indicate net climb). Courses with any amount of drop may be certified, but for record eligibility, drop must not exceed 1.0 m/km (USATF Rule 265.5(a)).
Separation - Straight line distance between start and finish expressed as a percentage of the race distance. Courses with any amount of separation may be certified, but for record eligibility, separation must not exceed 50% (USATF Rule 265.5(b)).
City - City where the course is located.
State - State where the course is located.
Course Name - Self-explanatory.
Status - These codes are formed from the values:
Sometimes, two or more letters are used in combination. For example, "AV" means "Active and passed validation."
Year Certified - Year in which the course was certified. A course expires on December 31 of the year determined by adding 10 to the year of certification.
Measurer - Name of the person who measured the course.
Replaces - If this course replaces an older one, this column displays the ID number of the older course that got replaced. This does not imply the old course is unusable as it's still Active.