Green Circles
In North America, trails marked with green circles are the easiest runs on the mountain. These trails are typically wide with a slope gradient of less than 25 percent.
Blue Squares
Trails with blue squares at North American ski resorts indicate intermediate difficulty. With grades of 25 to 40 percent, these ski runs tend to be the most numerous and most heavily used.
Black Diamonds
Ski trails marked with a black diamond at U.S. and Canadian resorts are considered to be difficult, typically with steep gradients exceeding 40 percent. Double black diamond trails are for experts. Only exceptional experts should try triple black diamond runs like Black Hole at Vermont's Smuggler's Notch.
Orange Rectangles
Orange rectangles with rounded corners typically are used to designate terrain parks that feature jumps, half-pipes and other specialty obstacles.
Rest of the World
European ski resorts use green to designate beginner trails, blue for easy, red for intermediate and black for experts. Resorts in Japan, where skiing is very popular, also use green for beginner runs, while red is for intermediate slopes and black indicates expert difficulty. Many skiers say that the green beginner slopes in New Zealand are as difficult as many blue square runs in North America. In New Zealand, blue trails are considered intermediate and black runs are the most difficult at ski resorts.
