Crumbly Knob Falls is a long, cascading waterfall about 100 feet high. It is located on a tributary of Smith Creek between Anna Ruby Falls Road and Tray Mountain Road. Due to the slant of the waterfall, its entire drop is hard to see at once unless the leaves are off the trees. It is best seen in wet weather. Accessing it from either road requires a bushwhack. You may be able to initially follow bits and pieces of an old logging road upstream from Anna Ruby Falls Road, but there's lots of debris.

To learn about more waterfalls in the Helen area, see chapter 6 in Mark Ozboyd's "Waterfalls of Georgia" guidebook.