June 1st: Lace up your boots and head to your favorite hiking grounds—it's the tenth annual National Trails Day. www.americanhiking.org

June 16th-18th:

Race Across America
Ready, set, Gu! About fifty ultracyclists set out from Portland, Oregon, for a 2,992-mile, 5- to 10-day race across the heartland to Pensacola Beach, Florida, in the 20th Race Across America, the longest and toughest single-stage bike race in the world. www.raceacrossamerica.org

15th: Seven hundred runners will line up for the Midnight Sun Marathon and Victell Half Marathon in Tromsø, Norway, where they'll race through the Arctic night under sunny skies. www.msm.no

24-28th: Cavers of the world unite at the National Speleological Society's Annual Convention, in Camden, Maine, to discuss conservation and geology, and to battle it out in the annual ramen-noodle wrestling contest. www.nss2002.org

24-30th: If weather and permits allow, mountaineer Christine Boskoff begins her bid this week to become the first American woman to summit 28,250-foot K2, the second-highest peak on earth. www.k2ascent.com

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