The sale of 435 acres in Rosemount paves the way for a sprawling new development with upwards of 2,000 houses and apartments and a new elementary school on land that was owned by the University of Minnesota.

"The site is the single largest proposal we've had in Rosemount," said Eric Van Oss, economic development coordinator for the city. "And the property is probably one of the bigger development sites in the metro area."

The closing comes after several years of creating a master plan for the site, which is part of a much larger redevelopment project in the city. Basic elements of the proposed project, known as Amber Fields, were approved last fall.

In addition to the housing and a badly needed elementary school, the project will also include upwards of 100,000 square feet of commercial space, parks and open space.

"You don't see many nearly 500-acre sites anymore," said Twin Cities-based Mario Cocchiarella, CEO at Maplewood Development, which paid $13.1 million for four parcels through an entity called Earl Street Partners, according to a certificate of real estate value filed Tuesday.

Cocchiarella said that if weather cooperates, he'll start building roads and other key infrastructure in late February.

The first order of business, he said, it to build a "spine road" and water main toward the north end of the site. Most of the multifamily housing — traditional rental apartments, townhouses and single-family rentals — and commercial development will be north of that new road.

Cocchiarella estimated that 20 to 25% of the housing on the site will be rentals, but most will be for-sale houses. He noted that all of the "vertical construction" will be handled by other builders.

"I'm a land developer," he said. "I grade the site and build the roads and do all the underlying construction."

He said the multiphase project will take about five to eight years.

Demand for housing in the fast-growing city has been strong, creating a deepening shortage of options for buyers. And that's caused higher-than-average price increases in Rosemount.

From January through November of last year, there were nearly 7% fewer house listings in the city compared with the previous 11-month period, according to the latest data from the Minneapolis Area Realtors.

On average, houses in the city sold in just 22 days during November, nearly 30% faster than the year before. And buyers on average paid nearly 103% of the seller's asking price, causing the median price of all closings during the month to increase more than 15%.

The property, which borders Dakota County Technical College and is south of 145th Street E., was part of a 4,772-acre property that was owned by the University of Minnesota and is known as UMore Park.

In 2015, the university's Board of Regents approved a plan to sell the property in chunks to a variety of developers who would create housing for 20,000 to 30,000 people.

The university was given the land by the federal government in the late 1940s and has used it for research and education through the decades. The government early in the decade bought more than 11,000 acres from local farmers for an ordnance site. A gunpowder production facility came online at the site near the end of World War II. Today, only remnants of the facility remain on nearby land.