The Ski Lifts section of the event graph comprises the ski lifts and queues for the lifts. If a skier takes a trail that leads to a lift, then the Trailhead event calls the Queue event with the arrow that enters Queue from above. The skier is placed into the queue for the lift as specified by the parameter CHOICE. The lifts are started by the Start Lifts event using the arrow that enters Load Lift from the bottom. Load Lift simulates a chair arriving for skiers to load; the event reoccurs with the same frequency that chairs arrive on the lift it models. The Load Lift event sends the minimum of the capacity of a chair on the lift and the number of people in the queue up to the Unload Lift event after the amount of time that it takes to ride the lift to the top. Unload Lift sends one skier to the Probability Calc event to determine which ski run or lift the skier will take next. If there are still skiers to unload, Unload Lift will call itself until all skiers are unloaded.