ST. LOUIS—HREC Investment Advisors has just arranged the sale of the 440-room Crowne Plaza St. Louis Hotel located near the landmark Gateway Arch in downtown St. Louis. It’s another sign that the city’s CBD is getting transformed into a residential neighborhood. The buyer was 200 STL Holdings, LLC which plans to convert the building into a mixed-use project with a 140-key boutique hotel and 300 residential units.

HREC’s Geoff Davis, its Denver-based president and senior principal, Scott Kaniewski, senior vice president and Ted Anka, vice president, represented Hallmark Hotels, LLC during the transaction. The price was not disclosed.

“The hotel’s location across from the Gateway Arch speaks for itself,” says Kaniewski. “The buyer plans a transformative project to continue to promote the renaissance of downtown St. Louis. We are pleased to have arranged a successful transaction for both the seller and buyer.”

The 29-story building is directly across from Jefferson National Expansion Memorial Park and has unobstructed views of the Arch, Mississippi River and St. Louis skyline. Furthermore, it is near other major St. Louis attractions, such as the new Busch Stadium, the Edward Jones Dome, and the America’s Center convention complex.

“A fair number of downtown buildings have been acquired for the purpose of conversion to residential,” Peter G. Harwood, executive vice president of capital markets at JLL, told GlobeSt.com. In fact, during the past five years, the downtown population grew by over 28%, and in the last ten years it grew by more than 124%.

Other new downtown apartment properties currently under development include: The Tower at OPOP; The Arcade, a historic rehab that will house over 200 artists; and The Alverne, another historic renovation that will offer two-story townhome style units. And the new Busch Stadium includes the master planned Ballpark Village project, a $650 million mixed-use retail and entertainment and residential development.

Perhaps most important to the CBD’s new residents is the $380 million renovation of the Gateway Arch. The project, called CityArchRiver 2015, will for the first time connect the CBD to the riverfront and the park surrounding the Arch with one continuous greenway. For decades, people in the downtown were cut off from these amenities by a highway. “It is on schedule for completion in 2015,” Harwood said.