Three separate runs in a span of 24 to 36 hours. Riding in a van with sweaty, tired teammates for hours at a time. Ingesting some calories and catching some sleep whenever you can.

Sound like much fun to you? The more than 2,000 individuals on nearly 200 teams scheduled to participate in the fifth annual Cascade Lakes Relay would likely answer in the affirmative, as the race seems to be growing in popularity.

According to Carrie McPherson Douglass, CLR assistant race director, the 2012 race sold out in just 30 days and race organizers were forced to turn away another 150 squads. (Registration for this year’s event opened in October 2011.)

This year’s CLR, scheduled for this Friday and Saturday, is a 216-mile running race from Diamond Lake (in the Cascade mountains of eastern Douglas County, north of Crater Lake) to Summit High School in Bend. Similar in format to its famous cousin, the Hood to Coast Relay, the CLR features teams of 12 runners (or fewer) tackling a total of 36 relay legs that vary in length from 2.1 to 10.5 miles.

Walking and high school teams participate in a shorter 132-mile relay from Silver Lake (in northwestern Lake County) to Summit High.

To get an idea of what it’s like to participate in the CLR, I spoke recently with several veterans who plan to take part in the event again this weekend. Melanie Mangin, business manager of the running shoe store FootZone in downtown Bend, runs for a team called In the Zone. Bend residents Katie Caba and Jason Adams compete on the teams Rebound/FootZone and Sole Brothers, respectively.

“It’s just kind of like, run, recover, eat, and then try to sleep a little bit and run again,” said Caba, a local standout runner, of the rhythms of participating in the Cascade Lakes Relay. Her mixed-gender Rebound/FootZone team has been the overall winner of every edition of the CLR and last year set the course record of 23 hours, 21 minutes, 7 seconds.

The relay is similar in concept to a track and field relay but spread across much longer distances. The runners on each team take turns running their individual legs. Upon reaching the race’s designated exchange zones, each incoming runner transfers a “slap bracelet” that serves as a baton to a teammate, who then proceeds down the road. When not running their own legs, race participants pile into team vans — two per team — and support their teammates out on the course, drive to the next exchange zone or perhaps catch a little shut-eye at designated sleep areas.

Caba described the course, much of which is on lightly traveled roads, as “gorgeous” and on “country roads.”

“The only people you really see are the ones that are doing the race, so I think that that’s kind of cool,” she said. “And it just makes for really great scenery.”

The CLR’s 36 legs vary considerably in terms of difficulty. Ratings are determined by length and elevation profile. Mangin pointed out that the 8.7-mile Leg 5 is a “nasty leg.”

“It’s not so much hilly, but it’s on a red cinder road, and the vans drive on that road also,” she said of Leg 5, on Klamath County Road 677. “And it’s not very wide, it’s a forest road, and it’s hot and dusty.”

Both Caba and Adams mentioned Leg 32, one of two designated time trial legs in the CLR, as a particular challenge. The leg is only 4 miles in length, but runners who tackle it must traverse the steep grade up Cascade Lakes Highway to the exchange at Dutchman Flat Sno-park. The leg includes 1,000 feet of elevation gain, but as a little incentive, the man and woman who post the fastest times on Leg 32 win a free pair of shoes from Fleet Feet Sports of Bend.

“We’ll give our biggest cheers for whoever is running on that leg,” said Adams, who in May finished fifth in the men’s elite division of Central Oregon’s Pole Pedal Paddle multisport race. Adams said he once urged on a teammate running Leg 32 by briefly racing alongside him as spectators do during the Tour de France cycling stage race.

In addition to the time trial legs, race organizers have come up with various contests to spice up the CLR. Adams and Mangin both brought up Leg 29, the 2.1-mile costume contest leg along Elk Lake, during which each team can display its sense of humor and dress up one of its runners. Mangin recalled one participant who dressed up as an outhouse.

“They had pictures of their teammates standing outside of it like they’re waiting to go into the outhouse,” Mangin said.

She recounted how another runner shed his clothes during the leg, stripping down to his briefs in homage to Will Farrell’s race car driver character in the comedy film “Talladega Nights: The Ballad of Ricky Bobby.” Coincidentally, Adams was similarly attired last year when he sprinted the costume leg at about 6 in the morning dressed in Speedo swimming briefs, aviator sunglasses and a backward visor.

“The guys were very much surprised,” he said.

Runners taking part in their first CLR can get ready to make some new friends — or get even closer to old ones — in the tight confines of those vans. Caba mentioned the close friendships she has cultivated through her participation.

All just part of the fun at the Cascade Lakes Relay.