Ceremonial Start

The race starts the first Saturday in March, at the first checkpoint on Fourth Avenue, in downtown Anchorage. A five-block section of the street is barricaded off as a staging area, and snow is stockpiled and shipped in by truck the night before to cover the route to the first checkpoint. Prior to 1983, the race started at Mulcahy Park.

Shortly before the race, a ribbon-cutting ceremony is held under the flags representing the home countries and states of all competitors in the race. The first musher to depart at 10:00 a.m. AST is an honorary musher, selected for their contributions to dog sledding. From the first race in 1973 until 1980, the honorary musher was Leonhard Seppala, who covered the longest distance in the 1925 diphtheria serum run. The first competitor leaves at 10:02, and the rest follow, separated by two-minute intervals. The start order is determined during a banquet held two days prior by letting the mushers choose their starting position. Selections are made in the order of musher registrations and mushers may choose any position that has not been previously chosen. The teams are helped to the starting line by several handlers and lined up at the starting line while the musher sets their brake in anticipation of the signal to start.

On the sled will also be an "Idita-Rider". The Idita-Riders purchase via auction in the preceding January the right to ride; the first auction was held entirely online for the first time in 2005. In 2005, the average bid was USD $1918.09, and raised a total of $140,021.00. This is an exciting portion of the race for dogs and musher, as it is one of the few portions of the race where there are spectators, and the only spot where the trail winds through an urban environment. However, In "Iditarod Dreams," DeeDee Jonrowe wrote, "A lot of mushers hate the Anchorage start. They don't like crowds. They worry that their dogs get too excited and jumpy." The time for covering this portion of the race does not count toward the official race time per rule #55, so the dogs, musher, and Idita-Rider are free to take this all in at a relaxed pace. The mushers then continue through several miles of city streets and city trails before reaching the foothills to the east of Anchorage, in Chugach State Park in the Chugach Mountains. The teams then follow Glenn Highway for two to three hours until they reach Eagle River, 20 miles (30 km) away. Once they arrive at the Veterans of Foreign Wars building, the mushers check in, unharness their teams, return them to their boxes, and drive 30 miles (50 km) of highway to the restart point.

During the first two races in 1973 and 1974, the teams crossed the mudflats of Cook Inlet to Knik (the original restart location), but this was discontinued because the weather frequently hovers around freezing, turning it into a muddy hazard. The second checkpoint also occasionally changes due to weather; in 2005, the checkpoint was changed from Eagle River to Campbell Airstrip, only 11 miles (18 km) away.