ROHNERT PARK — Visitors to Graton Resort & Casino just to the northwest of Rohnert Park will soon have a place to stay and relax by the pool in a major expansion unveiled last week.

Groundbreaking for a much-anticipated hotel at Graton Resort & Casino took place today on a 342,000-square-foot resort addition with a six-story, 200-room hotel, making it the fourth-largest hotel in Sonoma County. It will also feature a spa, pool and 20,000 square feet of more convention and meeting room space, the Federated Indians of Graton Rancheria said at a press conference this morning at the site.

“This is needed; it’s the icing on the cake," said Greg Sarris, chairman.

He said that the casino in two years has become highly successful. The casino's Facebook page is said to have the fifth-highest number of "likes" for such a facility.

Construction of the $175 million expansion will take place on the south side of the casino and connect to it via a passage next to the existing Daily Grill restaurant. The project is set to employ 1,000-plus during the job, which is set to be complete in fall 2016, and involve nearly 100 California companies.

Friedmutter Group is the designer, and The PENTA Building Group is the general contractor. Both are based in Las Vegas.

The guest rooms are set to range in size from 500 to 2,600 square feet.

A “centerpiece” of the expansion is the pool area, which is designed to extend from the hotel lobby and connect with the meeting space, Sarris said.

On June 30, the casino paid $12.5 million for 34 acres of surrounding land, according to public records.

A Moody’s Investor Service report in January said the tribe secured a $450 million bank facility for Graton Resort & Casino. The deal would enable the tribe to spend up to $200 million on a hotel.

The $800 million casino opened November 2013 with a wide variety of gaming, an 8,700-square-foot events center for concerts and special events and a dozen restaurants.

Graton Resort & Casino (GratonResortCasino.com) is owned by the Federated Indians of Graton Rancheria and managed by Las Vegas-based Station Casinos LLC.

This project comes amid other hotel developments in Rohnert Park.

The city is selling property for $7.15 million to a hotel developer that, with a retail partner, plans to build a hotel with 125 to 300 rooms. There will also be corresponding retail development, with the details to be determined.

The buyers are currently active in due diligence, which could last until November.

“This is part of Rohnert Park’s becoming more established as a tourist destination,” said Don Schwartz, assistant city manager.

The sale is for 12.25 acres of vacant land, also known as “Stadium Lands,” located at 5870 Labath Ave. The buyers are two private Southern California business organizations. MJW Investments LLC, based in Laguna, is the equity partner in the project, and 356 Advisors, out of Long Beach, will be undertaking the development of a hotel on the site.

A five-story Oxford Suites hotel is currently under construction near the Graton Resort and Casino. Located at 67 Golf Course Dr. W., the 163-room hotel is scheduled to open late in 2016.