The heroes and villains of the DC Universe have proven flexible enough over the years to appear in all types of stories, settings, and genres thanks in no small part to the Elseworlds line of stories.
One of the most surprisingly endearing for the Justice League is to see them (along with some of their greatest foes) reimagined as part of another classic American action-genre: the western. So what happens when the heroes and villains of the DC Universe are reimagined with an old west aesthetic?
EARTH-18
Based on a Post-Crisis Elseworld story titled "Justice Riders" by Chuck Dixon and J.H. Williams III, Earth-18 of the current DC Multiverse is home to the Justice Riders. A band of heroes brought together in opposition to the classic Legion of Super-Heroes villain the Time Trapper, the heroes inhabit a world where culture was frozen in the late 19th century -- ensuring the continuation of the cowboy aesthetic, sensibility, and technology into the modern-day.
The team is comprised of a mix of classic western DC characters (such as Bat-Lash, Strongbow, Ohiyesa Smith, El Diablo, Cinnamon, Firehair, and the Trigger Twins) alongside cowboy reinventions of more notable superheroes. This includes Madame .44 (this world's Wonder Woman), Tomahawkman (a gun-toting steampunk version of Hawkman), Johnny Thunder (a pistol-packing equivalent to the Flash), and Saganowana (this world's Manitou Stone-empowered Superman). The team has shown up in some stories but unfortunately for Johnny Thunder, this included being killed by the core-DC Universe Zoom in a surprise attack.
RETURN OF BRUCE WAYNE
In the aftermath of Final Crisis, Batman was sent tumbling through time as a result of Darkseid's Omega-Beams. Being shunted through different time-periods, an amnesiac Bruce Wayne is forced to readopt his Batman persona in different forms across human history. One such trip landed him in the Wild West in Grant Morrison and Georges Jeanty's Batman: The Return of Bruce Wayne #5. Fashioning himself as a gunslinger (who actually just uses Batarangs instead of pistols), Batman quickly becomes a persistent thorn in the side of Vandal Savage.
Already at work with Thomas Wayne (who will eventually go on to become Simon Hurt in the present day), Savage is forced to hire Jonah Hex to deal with Batman. Batman can save a kindly couple carrying a very valuable parcel -- a diary hinting at Batman's journey through time and what could come of it. Batman did his best to protect them and the journal but was eventually shot down by an unaware Jonah Hex in a dual. Although Bruce seemed to die when he fell into the nearby waters, he'd ensured the couple -- now revealed to be his direct ancestors -- built Wayne Manor on a nearby cliffside and hid the journal within the cave beneath it.
SIX-GUNS BLAZING
Gail Simone and Jim Calafiore's Secret Six #24 is a brief western interlude within the series about somewhat heroic villains. Taking place in an old west reality, Scandal Savage is the Sherriff of a small town. With Bane as her deputy and Liana as her gunman/girlfriend, she tries to protect the town from her world's equivalent of Alex Merkel, aka the demented and murderous Junior. The bounty hunter Deadshot rides into town to deliver several bodies to the sheriff and is in the local saloon flirting with Jeanette when this world's version of Catman -- surviving an attack by Junior's men -- arrives to take revenge.
The town clown, Ragdoll, reveals to the people assembled at the tavern that Junior is coming -- with this world's version of Deathstroke at her side. Arriving with a band of killers by his side, Deathstroke quickly kills Scandal and Liana. Deathstroke tries to kill Deadshot as proof of his skill but sets himself up to be blinded by the bounty hunter. Seeing an opening, the rest of the anti-heroes rush into action. Bane breaks Deathsroke's back and the group manages to bring down many of their attackers. But in the end, they're all overwhelmed and shot down by Junior's men, leaving the town to burn and the citizens to be slaughtered by the cruel Junior.