The job as Course Marshals is one of course security. Some Marshals will also be asked to help marshal skiers before the start of the event.
Marshals will be assigned positions at various points on the race course where there is the possibility of non-racing people getting in the way of the racers. An example would be at places where non-racers will be crossing the course to get to non-race trails. This is important to protect both the athletes and the folks just out to enjoy our beautiful trails.
Since Marshals will be on course, you will be there to cheer on and encourage the athletes as they ski by, be the eyes and ears for the medical team and may assist course set crews.
The marshals will have hi-vis vests so that people will know that they have some level of authority and not just some person giving grief to others using the trails.