Penn submitted an application last month for a concept plan review with the city of Henderson that outlined plans for a new 375-room hotel tower, 40,000-square-foot convention center and multiplex theater at the M, located at the corner of Las Vegas Boulevard and St. Rose Parkway at the valley’s southern edge.

The plans were scheduled for a city staff review last week.

Representatives for Penn did not respond to requests for comment Monday.

The Pennsylvania-based casino operator announced a $206 million expansion for the M in October, saying the second tower would add 384 rooms and 15,000 square feet of meeting space. It said in a news release that it planned to start construction this year.

As it stands, the 390-room M Resort boasts more than 90,000 square feet of casino space and several restaurants and bars.

The M’s expansion isn’t the only resort development in the pipeline for Henderson.

Station Casinos filed plans for a 600-room project in the Inspirada community. The resort would be built in three phases and feature more than 80,000 square feet of casino space, as well as retail, restaurants, bars, a bowling alley, movie theater and meeting space.

The Henderson City Council in early 2021 also approved plans to sell nearly 9 acres of city-owned land across from the M to the resort’s original developer, Anthony Marnell III.

Under the terms of the sale, Marnell has several years to close the purchase, albeit at an escalating price the longer it takes. The sales price will range from roughly $4.3 million to $6.2 million, city documents show.

Marnell, chairman and CEO of Las Vegas-based Marnell Companies, told the Review-Journal on Monday he will close the purchase but doesn’t know when. He also doesn’t have a timeframe for when he might start construction on a resort there.

Plans call for Marnell to build a hotel-casino and invest at least $250 million in the project.

Marnell said he loves the location but pointed to the M’s expansion and Station’s new project, adding that these other casino operators are actively underway on their plans. “I’m not in any hurry to just go build another casino,” Marnell said, noting the timing has to be right.

The M was in the works before Las Vegas’ frenzied real estate market crashed well over a decade ago, but ultimately, the resort opened its doors on March 1, 2009, amid the worst recession in decades.

Marnell has said it cost around $750 million to develop the resort. Penn, formerly known as Penn National Gaming, bought the debt on the project in 2010 for $230.5 million and took control of the resort the following year.

Marnell stayed on as president but left the M in 2015. His firm isn’t done with the project, though. Penn announced last fall that Marnell Architecture, which is under the Marnell family’s corporate umbrella, is designing the M’s second tower.