The long-awaited development of one of the state’s premier plots of empty land was triggered late Monday by the selection of a master developer from a group of three big players vying to drive the project.

Alatus LLC, overhaulers of the once-troubled Block E in downtown Minneapolis, will oversee the creation of Rice Creek Commons, a 427-acre area better known as the long-vacated Twin Cities Army Ammunition Plant (TCAAP) site in Arden Hills.

Ramsey County, which owns the property, and the city of Arden Hills want to turn the huge open space near the confluence of three major thoroughfares — Interstates 35W and 694 and Hwy. 10 — into a solar-powered eco-village that they hope becomes a national model for suburban development.

Arden Hills Mayor David Grant praised the Alatus-led team for its “attention to vision, to quality, to a sense of place, to a sense of something special.”

Private development of the munitions site is slated to begin in late 2017 or early 2018.

The decision by a joint county-city commission took less than 20 minutes. It was strongly hinted at in a staff memo praising Alatus’ choice of residential development partner: Tradition Development, creator of the 300-plus-acre Cobblestone Lake project in Apple Valley and an area that planners for the ammo site had toured for inspiration.

“Tradition builds a variety of upper-scale residential products, utilizing high-quality finishes,” the staff memo said. “Their communities stress aesthetic cohesion and a product that is not ‘cookie cutter’ in terms of appearance.

“They build a large number of amenities, and utilize unique characteristics of existing site features such as the Barn at Spirit of Brandtjen Farm,” a community gathering place in that Lakeville development.

Competing teams that made the shortlist of three finalists had chosen national firms associated with more conventional suburban subdivisions.

Opus Development Co. LLC, the firm behind Maple Grove’s town center project, Arbor Lakes, paired with subdivision developer Pulte Homes. And Ryan Companies, now developing projects near the new Minnesota Vikings stadium in downtown Minneapolis, teamed with Lennar Corp., which has long topped the list of Twin Cities homebuilders.

It wasn’t the first time Ryan had expressed interest in the site. It backed out of a massive redevelopment in 2009, just as the economy was bottoming out, saying the project wasn’t economically feasible.

In 2011, the Vikings said they badly wanted to build a stadium there. But when funding stalled, the team won state approval for a public-private partnership to build instead in Minneapolis.

Ramsey County Commissioner Rafael Ortega described Opus as his first choice, saying he wanted to “keep the county whole” after it “went out on a limb” financially in buying the Arden Hills property from the federal government and arranging a pollution cleanup to residential standards.

But he added: “I also want us, moving forward, to be a team here, and I will go with the majority as we seek to make this a reality.”

Commissioner Blake Huffman stressed that the selection of Alatus was just the first step. “We now need to negotiate both a development agreement and a purchase agreement,” he said.

Issues could include the degree of housing density the development will want to support; nearby stores and the like, with Arden Hills wanting to ensure it isn’t so urban as to not fit into a suburban landscape, and the nonresidential components.

The county and the city are keen to have a live-work-play town center, with offices and a walkable retail environment. But the private-sector aspirants warned about challenges, such as filling office space in today’s commercial real estate environment.

Mixed-income aspirations also will come into play. The staff memo praised the Alatus group for promising to “work with a wide variety of smaller builders to achieve an ideal market mix of starter, midrange and higher value homes and create aesthetic differentiation.”