DES MOINES — Muscatine, Sioux City, Cedar Rapids, Marion, Iowa City and Oskaloosa are the final six Blue Zones communities in Iowa, Gov. Terry Branstad and Healthways officials said Wednesday.

The announcement capped off a more than a year of competition between Iowa cities, big and small, to be chosen a Blue Zone. After two tries, Davenport was not named a Blue Zone community.

The name comes from a book by Dan Buettner, who traveled to places in the world where a higher percentage of people live longer, healthier lives compared with global averages.

In Iowa, the designation means communities will get extra help from Healthways experts in implementing Blue Zones blueprints in their cities and towns.

A winter storm that hit overnight in many parts of Iowa significantly reduced the expected turnout for Wednesday’s event, but some from the winning cities were able to be on hand for the announcement.

“Yes, it was worth it,” said Sue Brown, co-chair of the Sioux City Blue Zones initiative. Her initial group of 40 was reduced to three because poor driving conditions convinced some not to make the trip.

It was the second time Sioux City had tried for the Blue Zones designation. First-round winners — Cedar Falls, Waterloo and Mason City — were announced in May.

“We reached out to more people, we got involved with some more of those diverse populations and I think we did a good job of articulating that on our addendum to our Blue Zones project submission,” Brown said, explaining what she thought made the difference for Sioux City this time around.

The northwestern Iowa city is one of three communities selected Wednesday where work will begin immediately on putting together the Blue Zones plan, said Janet Calhoun, director of innovation and Blue Zones Project coordinator. Cedar Rapids and Muscatine are the other two. The remaining three communities will begin their work in 2014.

Davenport officials expressed disappointment that the city was not chosen, but they promised to forge ahead. The city will pursue self-directed methods to meet the Blue Zones certification level.

“Although Davenport wasn’t selected, we will continue to work to improve the health and well-being of all Quad-Citians and support the governor’s goal of becoming the healthiest state in the nation,” said Jason Gordon, a member of the Davenport City Council. Gordon has been active in heading up wellness initiatives around the city.

Davenport is poised to become certified on several fronts, said Theresa Hauman, the senior recreation manager for the city’s Parks and Recreation Department. Hauman cited the Quad-Cities Health Initiative and its new nutrition, physical activity and weight panel. That’s a Quad-City-wide effort to promote wellness and affect people in their daily lives at school, work and home, she said.

“We are more than prepared to move forward with our wellness initiatives,” she said, adding that Davenport will work with the Blue Zones process to become certified as quickly as possible.

John Forsythe, the CEO of Wellmark, said that with the new communities, one in six Iowans are now living in Blue Zones communities. Buettner said that is a “clearly a tipping point” in the state because the population is large enough that healthy lifestyle habits will likely be copied, even by those who do not live in the designated Blue Zones community sites.

“We’re talking to restaurants about having healthy items on their menu. We already have a lot of road races, but we’ll have more road races that we’ll be sponsoring, those kind of things,” said Rep. Mark Lofgren, R-Muscatine, a member of the Muscatine Blue Zones committee who took the trip from the Statehouse to Wellmark’s offices in downtown Des Moines for the announcement. “I feel if you just make a few good choices early, it will make a big difference in your health.”

Branstad is a big supporter of the Blue Zones Project as it dovetails with his push to make Iowa the healthiest state in the nation.

“I truly believe this is the opportunity to change in our state,” he said before announcing two of the six cities Wednesday. “We’re trying to turn this big battleship that was headed in the wrong direction.”

(Times reporter Deirdre Cox Baker contributed to this article.)