ANCHORAGE, Alaska (AP) — The 38th running of the world's most famous sled dog race kicks off tomorrow amid depleted finances that have slashed the cash purse even as the cost of competitive mushing continues to climb.

Yet the mystique of the 1,100-mile Iditarod Trail Sled Dog Race keeps drawing mushers from outside the state, including a first this year — a rookie from Jamaica. Also running are five past winners, including defending champion Lance Mackey, a throat cancer survivor from Fairbanks who is going for a fourth consecutive win. Another strong contender is Canadian Hans Gatt of Whitehorse who in February became a four-time winner of the 1,000-mile Yukon Quest International Sled Dog Race, which Mackey also has won four times.

The Iditarod begins Saturday with a ceremonial start in Anchorage. The actual competition gets under way Sunday in Willow, 50 miles to the north. From there, mushers leave festivities behind for a trail that crosses two mountain ranges, scores of Alaska Native villages, then a stretch of the frozen Bering Sea shore before it reaches the finish line in the old gold rush town of Nome on Alaska's western coast. It's a trail where temperatures can plunge to 50 below zero and fierce winds can wipe out visibility.

The total purse this year is $590,000 — down from a high of $925,000 in 2008 — with $50,000 of this year's prize money donated by four-time champion Jeff King, who also is in the running. Even the prize for the winner will be nearly $20,000 smaller than the $69,000 of past years. The winner still also receives a new Dodge truck.

"We're certainly having to work harder in these challenging economic times to raise the revenue that we'd like to raise to restore that purse to levels we accomplished a couple years ago," Stan Hooley, executive director of the Iditarod Trail Committee, said this week at a media briefing.

This year's race is the first time in Iditarod history in which mushers will be tested for drugs and alcohol, joining the canine athletes that have been tested for prohibited substances for years.

Mackey, 39, has acknowledged using medical marijuana on the trail, but said he is abiding by the new rule. He said he believes it was implemented to single him out and that other competitors have complained about his pot use — contentions Hooley is not denying.

"I don't think he's off base in what he's saying," he said.

Most other mushers interviewed say they have no problem with the policy.

Hooley said one of the Iditarod's newer sponsors is a drug testing company that is providing the service at no charge. "At a time when we've been forced to look and make some really hard budgetary decisions, it would not have been good timing to be spending new money on this program," he said.

Race organizers blame the money woes on a poor economy that led to a loss of almost $1 million in funding after major sponsors dropped their support and video deals collapsed. Cushioning the blow somewhat, Exxon Mobil has pledged $250,000 annually in a five-year deal and earlier this year, the city of Nome donated $50,000 to the race. The Iditarod also retains a few dozen other supporters.

At the same time, mushers say the cost of the sport is escalating, including the $4,000 entry fee — up $1,000 from the 2008 entry fee — dog food and other kennel expenses. Many wonder how long they can keep their teams, even though most get varying degrees of support from sponsors.

Iditarod veteran Paul Gebhardt, who has twice placed second in the race, figures it costs him $1,000 a year for each dog in his Kasilof kennel — and he has 75 dogs.

"We don't make a lot of money," said Gebhardt, 53, a general contractor in the offseason. "Even if you win, you're not going to get rich or anything. We do this as a lifestyle. But it's nice if it can pay for itself, so you're not going to the poorhouse doing it."

Iditarod spokesman Chas St. George said the cost of staging the race over a vast terrain also has gone up. Fuel used for transporting human and dog food to checkpoints and for other reasons has increased. So has the cost of straw for bedding the dogs as well as other supplies and services the Iditarod provides to mushers at the checkpoints.

"We understand the frustration," St. George said of mushers. "They're going through some tough times. We're going through some tough times."

Still, the lure of the longest sled dog race on the planet is too strong for some to resist, even from afar. More than one third of the field of 71 comes from seven other countries and nine other U.S. states.

Scottish rookie Wattie McDonald, 46, has spent about $100,000 preparing for the Iditarod, buying provisions, leasing a dog team, taking time off from work to train and race in Alaska. McDonald, a Stonehaven resident, has been mushing for 10 years, but nothing close to the level of the Iditarod, which commemorates a run by sled dogs in 1925 to deliver lifesaving diphtheria serum to Nome. For him, the adventure is worth the expense, the chance to be one with his dog team across incredible wilderness.

"It's such a life-changing experience, so far out of my comfort zone," McDonald said. "Minus-50, people even mention it, I just start shaking in my boots. But to be honest with you, I just can't wait to go there."