Registration opened to the public Tuesday for the Twin Cities Marathon.

The field already had 3,300 marathoners signed up. Some are last year's runners who missed out after the race was canceled by an intense heat forecast. They were given a special window to register late last year. There also was an early bird promotion Jan. 1, according to the race organizer, Twin Cities in Motion (TCM).

TCM spokesperson Charlie Mahler said Tuesday's response was positive.

"We are pleased by the registration we have seen so far," said Mahler, who added that TCM expects the marathon to sell out with 8,000 runners.

Another 12,000 are anticipated in the popular TC 10-Mile run. The lottery drawing for entry is in June. TCM also hosts marathon weekend races, including a 10-kilometer run and a 5K that draws thousands more.

Mahler said TCM is "doubly eager" to have a great marathon Oct. 6 after last year's last-minute cancellation — the first in race history.

"I think like for a lot of runners the TCM staffers have a year and a half of pent-up marathon energy we didn't get to experience last year in the way we wanted to experience it," Mahler said.

Find more details about this year's marathon and related races at tcmevents.org.