Two independent teams of paddlers led by Minnesotans have been pushing their canoes day and night to get down the Mighty Mississippi the fastest.

On Monday morning, one of them hit the "finish line" at the Gulf of Mexico and laid claim to a new mark, covering 2,300-plus miles in 17 days and 20 hours. If it stands up with the Guinness World Record-keepers who will vet it, the group will have bested a record that has stood since 2003. The previous mark was 18 days, four hours, and 51 minutes by a twosome in a canoe.

The apparent record-holders, KJ Millhone, 62, of Minnetonka and a team of four that included his daughter, Casey, left the headwaters of Itasca in late April. The other two team members of MMZero (a reference to "Mile Zero" on the Mississippi) are Bobby Johnson and Rod Price, of Florida, no strangers to long-distance paddling adventures.

The experience was familiar territory for Millhone, who set an earlier mark with friend Steve Eckelkamp in 1980 and has made other attempts since. Millhone couldn't be reached for comment Monday morning, but given the group's 24/7 routine of sleepless nights, barge traffic, wing dams, and more, that's not surprising.

A second foursome that left Itasca on May 4 is chasing a speed record of its own and has several states, hundreds of miles, and a boatload of grueling challenges ahead. Scott Miller, Perry Whitaker, Joel Ford, and Adam Macht still are in their first week and have hit northeast Iowa. (Track them here.) Coincidentally, Miller, of Minneapolis, and Millhone planned just such an attempt together in 2020 before COVID-19 spiked their plan.

Watching it all is Clark Eid of Huntsville, Ala., who with Bob Bradford of Michigan set the 2003 mark.

Eid applauded Team MMZero on Monday morning.

"They did a great job staying focused," he said in an email to the Star Tribune. "Fate was kind to them with high river levels at the start and end, and great weather on the sections of big water. Having a dedicated on-water support team was also a big plus!"

Eid recalled a lengthy application process to secure a "Guinness Certificate" validating that his record was legitimate.

The Guinness World Records' website says a records management team will "undertake substantial research and verification checks to confirm whether a new record title has been achieved."