Schafer Richardson is hopping the Mississippi River with a plan to build 175 market-rate rental apartments near the Xcel Energy Center in downtown St. Paul.

If approved, the project would be the first St. Paul project for the Minneapolis-based developer. And it adds to the transformation of one of the most historic corners of the city.

"There's opportunity in St. Paul and that's why we're interested," said Maureen Michalski, director of development for Schafer Richardson.

The company set its sights on a 1.3-acre, triangular parcel at 217 Chestnut St. that's a few blocks from the Science Museum and Mississippi River. The site is owned by the city and is now a surface parking lot.

Known as the Ryan lot, the parcel wasn't on the market and the city wasn't actively seeking a redevelopment proposal. "We are excited about the potential for a higher use of the site," said Mollie Scozzari, spokeswoman for St. Paul's planning and economic development department.

Schafer Richardson's proposal is still in its infancy. In a letter to the city, the company spelled out plans for a single U-shaped building with two six-story wings that would face Exchange Street and Eagle Parkway.

A portion of the building, designed by UrbanWorks Architecture, would have two-story walk-up townhouses that face Eagle Street Plaza park along Chestnut Street and Eagle Parkway.

The site slopes toward the river, enabling the developer to build two levels of enclosed parking. The project will have a full range of unit configurations, ranging from micro-sized apartments with about 400 square feet to multistory townhouses with three bedrooms.

Already, about 400 rentals have been proposed for nearby sites, according to Mary Bujold of Maxfield Research. The city will also soon issue a request for proposals to redevelop the Ramsey County Courthouse, which could accommodate another 200 or more housing units on the Ramsey County jail site, she said.

Scozzari said that what is happening in the West 7th Street neighborhood is an extension of a development boom in St. Paul's Lowertown and downtown neighborhoods.

"The economic vitality we are seeing up and down West 7th has been tremendous," she said.

At the corner of W. 7th and Kellogg, the Opus Group is replacing the venerable Seven Corners Hardware store with a massive apartment and retail complex.

It is also codeveloping a project called Seven Corners Gateway directly across from the Xcel Energy Center. The company wants to build a Radisson Red hotel, which could also include a public plaza and first-floor commercial space. And in late 2015, Cossetta's Italian Market and Pizzeria opened its dramatically expanded digs along the West 7th corridor and, late last year, Bad Weather Brewing opened up shop.

"The location is really unique in that you have downtown right there, you've got the commercial district and neighborhoods along West 7th, including historic Irvine Park," Michalski said. "This site is the point where all those various amenities and services come together."

Last week, Hampton Inn and Suites said it was building a 160-room hotel at 200 W. 7th St. The company said opening is scheduled for November.

The city has a 45-day comment period on the Schafer Richardson proposal, during which other developers can submit proposals, and then the HRA board will be asked to consider the sale of the site.

After completing its due diligence and moving through the entitlement process, Schafer hopes to begin construction sometime in 2017.