Scotland, run regularly since 1937, and the Snowdon Race in Wales. Overlap with other sports Fell running is often known as hill running, particularly in Scotland. It is sometimes called mountain running, as in the name of the Northern Ireland Mountain Running Association although the term mountain running often has connotations of WMRA races which tend to be on smoother, drier trails and lack the route choice which may be available in fell races. Fell race courses are often longer than cross-country running courses, steeper and unmarked when out on the hills (with a few exceptions). Fell running also overlaps with orienteering. Courses are again typically longer but with less emphasis on navigation. Fell running does sometimes require navigational skills in a mountainous environment, particularly in determining and choosing between routes, and poor weather may increase the need for navigation. However, in most fell races, the route or sequence of checkpoints is published beforehand and runners may reconnoitre the course to reduce the risk of losing time working out where to run during the race. Category O events and Mountain Marathons (see also below), test navigational ability, attracting both orienteers and fell runners. Other multi-terrain events, such as the Cotswold Way Relay and the Long Mynd Hike, also qualify as fell races under Fell Runners Association rules. Some fell running could also be classed as trail running. Trail running normally takes place on good paths or tracks which are relatively easy to follow and does not necessarily involve the significant amounts of ascent that are required in fell running. Rocks Fell running does not involve rock climbing and routes are subject to change if ground nearby becomes unstable. A small number of fell runners who are also rock climbers, nevertheless do attempt records traversing ridges that allow running and involve scrambling and rock climbing – particularly where the record is 24 hours or less. Foremost of these in the UK is probably the traverse of the Cuillin Main Ridge on Skye, the Greater Traverse, including Blaven and the Lakes Classic Rock Round. Organisations The Fell Runners Association (FRA) publishes a calendar of 400 to 500 races per year. Additional races, less publicised, are organised in UK regions. The British Open Fell Runners Association (BOFRA) publishes a smaller calendar of races (usually 15 championship races, and other smaller events, such as galas or shows)>– mostly derived from the professional guide races