It began as a way for cyclists to ride year-round through the harsh winter months. Today, the sport of snow biking has exploded, and with it on-snow races are popping up all over the continent. Here are eight of the most epic events around this year. —Amy Oberbroeckling

Iditarod Trail Invitational — Among the most remote races in the world, the Iditarod Trail Invitational is also billed as the world’s longest human-powered winter ultra. The race follows the famous Iditarod Trail in Alaska, giving racers the option of going for 350 miles or completing the whole trail and racking 1,100 miles under the wheels through remote Alaska in the black-cold heart of winter. Race starts February 24, 2013.

Arrowhead 135 — Outside of Alaska, Minnesota’s Arrowhead 135 is about the most grueling fat bike race around. Top racers from all across the world gear up each winter to pedal 135 miles along the Arrowhead State Trail during deep northern Minnesota winter where temps dredge to minus-30 F or further below. 2013 marks the 8th year for the race, beginning with 10 entrants in 2005 to about 135 starters in 2012. Begins on January 28, 2013, and racers get a little less than three days to make it to the end.

The Frosty Bottom 50/25 — If you’re looking for a shorter Alaskan adventure the Frosty Bottom 50/25 is a good fit. The annual winter ride, held entirely on the multi-use trails around Anchorage, gives racers the option of calling it “good” at 25 miles. Hardcore bikers retrace their tracks to finish a solid 50-miler on the snow. Race rolls off on January 5, 2013.

Noquemanon Fat Bike World Championship — Known as “The Noque” to locals, this cross-country ski race in the Upper Peninsula of Michigan is now open to bikers. The 50-kilometer race is a part of the new Great Lakes Fat Bike Series, which includes five snow-bike races around the Midwest. The Noquemanon Fat Bike World Championship takes off on January 26, 2013, after all the skiers have passed through the gate.

Yukon Arctic Ultra 430 — Advertised as “the world’s coldest and toughest ultra,” the Yukon Arctic Ultra takes place across 430 miles of snot-frozen Canadian wilderness. Competitors who dare race do so in temps that drop as low as minus-58 degrees Fahrenheit, the organization cites. This is not to mention the face-freezing winds to 50 miles per hour or more. Bring your warmest gear, or you might pack a space suit, for this one, which is held from February 3, 2013, onward into the white Yukon abyss.

Tuscobia Winter Ultra — Held on the Tuscobia State Trail in northern Wisconsin, this ultra has 35, 75, and 150-mile options. The long one is a qualifier for the Iditarod Trail Invitational in Alaska (see above). More race info is here.

Wyoming’s Togwotee Winter Classic — No entry fee and a field limit of 50 racers, the Togwotee Winter Classic is a grass-roots bike race held just north of Jackson Hole, Wyo. Racers choose from 25- and 35-mile options, a nice stepping stone for emerging snow-bike racers. The 6th annual race will be held March 9, 2013.

Fat Bike Birkie — The Berkebeiner, a famous annual cross-country ski race that travels the North Woods of Wisconsin, is open for the first time this year to fat bikes. This inaugural bike race will travel the hilly Birkie trail and will have 45K and 18K race options. Race date is March 9, 2013.

—Amy Oberbroeckling is an assistant editor. See a full calendar of snow-bike events on Fat-Bike.com. See the GearJunkie article “‘Fat Bike’ Trend: Overrated or For Real?” for more on the rise of snow-biking around the world.