His father's company, Marnell Corrao Associates, designed and built the M. Construction began on September 1, 2007, and the resort opened on March 1, 2009, amid the Great Recession.

In 2019, the M entered a partnership with the Las Vegas Raiders football team, which now rents out the hotel before games.

Tony's company, Marnell Corrao Associates, would design and build the M. The project received preliminary approval from the city of Henderson in October 2005.

[9] The M was built at the southeast corner of Las Vegas Boulevard and St. Rose Parkway,[10] in an area that was expected to see significant future development.

[5][11][12] The resort was built on property that was previously occupied by the Last Call Tavern truck stop.

[7][22] An M-branded blimp was flown around in Las Vegas and California to advertise the resort,[23][19][24] months prior to the opening.

[7] Value-conscious tourists were another target demographic;[15] Marnell felt that other Las Vegas resorts had begun to overcharge guests in recent years.

Marnell strived to recreate the Rio's former reputation for value and friendly customer service;[31][33] he believed that the latter would be critical to the M's success amid the economic downturn.

[30][34] Within days of its opening, the property experienced strong business and announced that it would hire an additional 250 employees to resolve long lines.

[39] Because of the recession, planned housing communities and businesses near the M were canceled, which eventually had a negative effect on the resort.

[40] Business saw a decrease during the summer months of 2009,[41][42] and MGM Mirage stated that its investment in the resort had lost its value.

[43] Business improved toward the end of the year,[44] after the resort served as the production location for Top Chef: Las Vegas in 2009,[45][46] boosting customer visitation.

[47] In December 2009, the resort featured the tallest non-living Christmas tree in the United States, standing 109 feet.

[48][49][50] In 2010, the General Services Administration held a controversial conference at the M Resort that later came under scrutiny, due to the high amount of taxpayer money that was spent.

[40] Penn National Gaming and Leonard Green & Partners both put up bids to acquire the debt.

[66] In 2019, the M entered a 10-year partnership with the Las Vegas Raiders football team, which had its headquarters a few miles from the resort.

[71] In 2022, Penn announced plans to eventually build a second hotel tower, part of a $206 million expansion which will also add meeting space.

[79] The casino also included a pharmacy for gamblers to get their prescriptions filled, and customers had the option of using slot club points to cover the costs.

[80][79] The pharmacy idea came from Marnell, in an effort to attract retirees, who made up a substantial portion of Henderson's population.

[86][87] Many of the resort's facilities surround a pool area and a permanent outdoor music venue; the latter is uncommon for a locals casino, but Marnell wanted to include such a feature for ambiance.

[88] During its first year, the M struggled to secure top entertainers for its outdoor venue, in part because of the resort's distance away from the Las Vegas Strip.

[10] Marnell owned and managed the restaurants and bars, unlike most casino properties which outsource them to third parties.

[95] The Studio B Show Kitchen Buffet offered seating for 500 people, and included space for live cooking demonstrations.

[40][101] One of the M's original restaurants, Veloce Cibo, operated on the top floor of the hotel tower and overlooked the Las Vegas Strip to the north.

[105] In 2013, chef Seonkyoung Longest won the reality television series Restaurant Express, which was produced in affiliation with the M Resort.

[106] Longest departed a few months later to pursue other interests, but the restaurant remained open,[107] eventually offering an all-you-can-eat format.