I can’t count the number of times I’ve heard a thru-hiker claim something like “the bubble is about a week behind you”. I decided to do some analysis on hiker comment data, to better model out where the bubble actually is on any given day, and what it might look like! This tool covers the hiker bubble for the Continental Divide Trail and the Pacific Crest Trail, and can tell you how many hikers are ahead of you or behind you on trail for a given mile and day.
Where is the bubble? Try it for your trail and date
You can switch between the CDT and the PCT with the trail menu drop down.
The snowpack is refreshed from NOAA data by a small daily job, and it is frozen at April 1st every year.
The time-lapse follows the comment density approach in the write-up. The line is the median date of direction-labelled comments within 75 miles either side of each mile, typical across hiking years, lightly smoothed and kept from running backward. The shaded band is the middle 80 percent of those comment dates at each mile. Additional information on the modeling that was done with the data can be found here.