The Iron Butt Rally first ran in 1984 with 10 riders.From 1984 to 1987 the rally started from Montgomeryville Cycle Center near Philadelphia, Pennsylvania. The Iron Butt was not held again until 1991 when it came under the management of the Iron Butt Association. While the basic format of the original rally remained, two important things changed: to ensure the quality of the event, the rally is run every other year, and the starting and ending points are rotated to different locations within the United States. 107 riders started and 89 finished the latest Iron Butt Rally, which ran in 2017.
Beginning in 1993, shorter rides were arranged that lasted in duration from one to many days, and while the Iron Butt Rally is a large, organized event with a plotted course, the other rides are left up to the competitor to accomplish at their own accord. Some riders prefer to complete a ride solo, while some clubs have arranged rides in groups of up to 30 riders. But while the Rally is a monitored event, the riders of other events must monitor themselves. An example is the Saddle Sore 1000, where thorough documentation of the ride must be made, by collecting time-stamped gas and business receipts along the way, and by keeping a trip log recording mileage and location. These documents are then submitted by mail with a fee to the IBA, where it is then processed and an award given if the requirements are met.
The Iron Butt Association has members around the world. Those in the UK run their own rally each year called the Brit Butt Rally. Riders from all over Europe, Norway, Middle East and Australia have entered. There is also a 12-hour teaser rally called the Brit Butt Light. Iron Butt UK has grown from 7 registered riders in 2005 to over 350 riders completing Iron Butt rides within the UK during 2009. Iron Butt UK also teamed up with the Royal British Legion Riders branch in organizing a 24-hour 1000 mile run with over 175 riders taking part. The previous world record was 152, however the UK riders were pipped to the post by another USA ride of over 400 riders.