There is limited information on most adventure recreation activities, often including even who partake and trends in the popularity of the activity. The adventure recreation sport of 'canyoning' grew rapidly in the Greater Blue Mountains World Heritage Area (Australia) in the 1990s. Canyoners are typically male, aged in their 30 s, educated, and their preference is to canyon in small groups with friends and families. However the popularity of this adventure sport has waned. Surveys between 2000 and 2002 showed that while canyoner numbers were similar in 2000 and 2001, they declined in 2002. In 2010 the numbers of canyoners were similar to 2002 visitation levels, approximately 40% below 2000 levels. The trend did not appear to be due to increased interest in active/extreme sports (e.g., mountain biking). Bushwalking (hiking) was the preferred alternative recreational activity for over 20% of canyoners at all experience levels. The trends observed between 2000 and 2010 parallel the overall number of tourists to the region, and the commercial canyoning activity. We conclude that at current and projected levels of canyoning, there is not an immediate threat to the canyon environment.