The Sierra Cup Regional Championship Mountain Biking Series for 2011 begins May 21 in Gardnerville.

The Sierra Cup is a seven race point series to determine the USA Cycling cross-country mountain bike champions for the Northern California/Nevada region. Top finishers at the first three events will also qualify to compete at the Mountain Bike National Championships in Sun Valley on July 14-17.

The Sierra Cup events are the Pine Nut Cracker on May 21 in Gardnerville; Peavine Challenge on June 5 in Reno; Skyline Park Mountain Bike Race on June 12 in Napa; Kirkwood Mountain Classic on July 30 at Kirkwood; Sky Tavern Classic on Aug. 14 in Reno; Great Tahoe Flume Race on Sept. 10 at Spooner Lake; and Sawtooth Ridge Challenge on Oct. 2 at Northstar-at-Tahoe.

Online pre-registration is available for all events.

These events take riders through some of best trails in the West and challenge them with heart pounding climbs and fun, technical descents. There are age and ability categories for all levels of riders. Race distances vary with each event and are often based on the ability categories.

The Sierra Cup is unique in that all of the participating races donate their proceeds to various nonprofit organizations that give back to the trails where mountain bikers ride. For more information, go online or email mtb11@renowheelmen.org.