Color key: yellow = <132ft/mi, 5% grade green = 132-158ft/mi, 5-6% grade light blue = 159-184ft/mi, 6-7% grade dark blue = 185-211ft/mi, 7-8% grade red = 212-238ft/mi 8-9% grade grey = 239-264ft/mi, 9-10% black = >264ft/mi or 10% grade