Alaska's Iditarod sled-dog teams embark on their 1,610 km race

March 4 (Reuters) - Dozens of sled-dog teams glided through the frigid streets of Anchorage on Saturday in the ceremonial start to the Iditarod, a nearly 1,000-mile (1,610-km) sled dog race across the Alaskan wilderness and one of the world's most celebrated tests of endurance.

The official start of the event billed as "the Last Great Race" will take place on Monday in Fairbanks, 350 miles (560 km) north of Anchorage, and ends in the coastal town of Nome.

"And they're off!," Senator Lisa Murkowski of Alaska said in a Twitter message. "Beautiful day in Anchorage for the start of #Iditarod 2017."

Organizers last month moved the official "restart" line from the town of Willow, an 80-mile (130-km) drive north of Anchorage, to Fairbanks because of insufficient snow along some trails in the Alaskan Range, which made it potentially unsafe to race through the mountains.

It was the third time in the race's history that the start line has been moved. The first was in 2003 and the second in 2015.

This year a field of 72 teams will compete in the event, which inspires pride and fascination among Alaskans and international audiences alike.

A website that tracks mushers and their dogs with the help of GPS technology enables fans around the world to monitor the progress of teams, which often endure gale-force winds, whiteout conditions and temperatures as low as -40 degrees Fahrenheit (-40 Celsius). It takes nine to 17 days for racers to complete the course.

The race is a tribute to a life line of mushers and dogs who carried essential supplies to remote outposts in the early days of Alaska's non-aboriginal settlement.

The most famous of those missions took place in 1925, when a relay of teams completed the legendary "Serum Run" delivering a crucial supply of antitoxin to Nome for children stricken by a deadly diphtheria epidemic.

Before Saturday's 11-mile (18-km) ceremonial run to Campbell Airstrip, thousands of well-wishers lined the streets of the state's largest city to cheer the racers, many of whom are local celebrities. Temperatures were hovering at 0 degrees Fahrenheit (-18 Celsius) at race time.

"I can't feel my toes, but this is pretty cool," wrote Twitter user Shannon M. Banaga, posting a picture of a young woman dressed in a fur-lined hat near the starting line.

While most of the mushers in this year's field are from Alaska, at least four other states are represented, as well as Canada, Czech Republic, England, France, Hungary, Norway and Sweden.

The field, with 55 veterans and 17 rookies, includes Dallas Seavey, the 2016 winner, and four other former Iditarod champions.

Seavey, a four-time Iditarod winner, set a race record last year with his time of eight days, 11 hours, 20 minutes and 16 seconds. Seavey, 30, the son of two-time Iditarod winner Mitch Seavey, took home a $75,000 purse last year. (Reporting by Frank McGurty in New York; Editing by Jonathan Oatis, Bernard Orr)