April 9 Brit explorers David Hempleman-Adams and Jock Wishart launch the POLAR RACE, in which 17 men and women trek and ski 350 miles from Resolute Bay, Canada, to the North Pole. www.polar-race.com

April 10-13 Sixty thousand cyclists descend on Monterey, California, for the SEA OTTER CLASSIC, the largest mountain- and road-biking jamboree in the United States. www.seaotterclassic.com

April 25-27 The PHOENIX BOULDERING CONTEST, the biggest outdoor bouldering event in the U.S., celebrates its 20th birthday. Six hundred climbers will compete outside Superior, Arizona, for $50,000 in cash and prizes. www.phoenixboulderingcontest.com

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