In 1907, the venue opened as the Mammoth Roller Skating Rink, becoming a prominent after-school hangout for the nearby East High School.
During this time, it also became the home venue for the Mammoth Garden Dodgers (which was a part of the Colorado Roller Hockey League) and a professional basketball team before the construction of the Denver Coliseum.
The venue worked closely with Barry Fey to bring national touring acts to the Denver scene.
Although only in business for eight months, the club hosted concerts by the decade's leading artists including Jethro Tull (band), The Who, The Grateful Dead, Johnny Winter and Joe Cocker.
In 1981, the venue was reopened under the "Mammoth Gardens" moniker to host sporting and music events while also servicing as a private meeting room and banquet hall.
During its 12-year run, the venue hosted various concerts, with such names as The Mighty Mighty Bosstones, Beastie Boys, Fishbone, Murphy's Law (band), Ozzy Osbourne, Cyndi Lauper, Pantera, Slayer, Club Nouveau, DJ Quik, Rick James, Cypress Hill, Siouxsie & the Banshees, Big Audio Dynamite, Jane's Addiction, Fugazi, the Offspring, Sublime, Butthole Surfers, Dream Theater, Blink-182, Oasis, Coldplay, Green Day and many others.
This was met with controversy among the Colorado audience and luminaries, many of whom felt Denver had an ample amount of music venues.
Promoter Barry Fey, who preferred not to use the venue, stated the unpopular opinion that "hell" had better connotations than "Mammoth".
Despite its challenges, the building was heavily renovated between November 1998 and May 1999, relocating the stage, fixing the acoustics and adding many amenities.
Since its 1999 opening, the auditorium has hosted concerts by Bob Dylan, Widespread Panic, NOFX, Morrissey, Foo Fighters, Bad Religion, Umphrey's McGee, Sound Tribe Sector 9, Marilyn Manson, Joss Stone, Nelly Furtado, James Blunt, Owl City, Armin van Buuren, Erykah Badu, Paramore, Ghost, AJR, Panic!