WSER meaning in Sports ?

The Western States Endurance Run, known commonly as the Western States 100, is a 100.2-mile (161 km) ultramarathon that takes place on California's Sierra Nevada Mountains trails each year on the last full weekend of June. The race starts at the base of the Olympic Valley ski resort and finishes at the Placer High School track in Auburn, California. The terrain is quite rugged, frequently showcasing snow on the highest passes and record hot temperatures throughout the course. Runners ascend a cumulative total of 18,090 feet (5500 m) and descend a total of 22,970 feet (7000 m) on mountain trails before reaching the finish. Because of the length, the race commences at 5 a.m. and continues through the day and into the night. Runners finishing before the 30-hour time limit for the race receive a commemorative bronze belt buckle, while runners finishing in under 24 hours receive a silver belt buckle.

The Western States 100 is one of the five 100-mile races that comprise the Grand Slam of Ultrarunning, which also includes the Old Dominion 100, Vermont 100 Mile Endurance Run, the Wasatch Front 100 Mile Endurance Run in Utah, and the Leadville Trail 100 in Colorado.