MacKenzie Porter and Anson Mount star in "Hell on Wheels"

Who doesn’t love a rip-roaring Western?

Throw in a major episode in America’s history and you’ve got “Hell on Wheels,” AMC’s exciting period drama surrounding the construction of the First Transcontinental Railroad across the U.S. The show’s fourth season kicks off Saturday, Aug. 2, on the cable network.

If you haven't caught the show before, Cullen Bohannon (Anson Mount, “In Her Shoes,” 2005) is a former Confederate soldier haunted by his past and driven to avenge the murders of his wife and son by Union soldiers during the Civil War. He joins the Union Pacific Railroad’s western construction in the first season, which is how he comes to Hell on Wheels – a lawless, mobile town that follows the railhead across the country to service its construction.

The series left a lot up in the air at the end of season 3, so fans will be glad to have a few questions answered this year. One of last season’s major driving points was the battle for control of the railroad between Bohannon and Thomas “Doc” Durant (Colm Meaney, “Star Trek: Deep Space Nine”), an entrepreneur and investor hoping to make his fortune with the railroad. Bohannon had finally turned the tables and gotten himself into a position of power, which, before the third season, had previously been held by Durant.

(Fun fact: Meaney's character is based off the real Thomas C. Durant, a 19th-century American railroad financier who was vice-president of Union Pacific in 1869.)

Then his circumstances changed. Bohannon ended last season as a married man. After discovering that he had gotten a young Mormon woman with child, Bohannon agreed to marry her.

“This is a man of integrity and this is a man of honor and he’s going to do the right thing,” says Mount in a recap of the season 3 finale.

One stipulation of his marriage is that he live at the Mormon fort, which means giving up his position with Hell on Wheels (beats hanging, though, which is the alternative). The actor has also hinted that this change in his circumstances will also begin to change Bohannon as a man.

He has a new set of responsibilities now that he has promised to be the father of Naomi’s (MacKenzie Porter, “The Horses of McBride,” 2012) child, which means he may have to tone down his recklessness and put himself in fewer situations that could potentially get him hanged. More than that, though, this season will give us a different side to Bohannon as a real love begins to form between him and the woman he married out of duty and necessity.

Executive producer and showrunner John Wirth has discussed the relative freedom cable writers have when it comes to character development and making major changes as a series progresses. As he told "Yahoo TV:"

Christopher Heyerdahl as seen in "Hell on Wheels"

“In the days prior to cable, when there were just three networks and we were all doing broadcast shows — 22 or 26 episodes a year — your main character really didn't change much. His or her circumstances might go from A to B in any given season. But on these cable shows, you can really radically change your characters' circumstances, and the audience stays with you.”

Bohannon's abrupt change in position -- and narrow survival -- wasn't the only thing that dropped viewers' jaws last season. Another major cliffhanger was the state of Elam Ferguson (Common, “Smokin’ Aces,” 2006), who wasn’t looking altogether alive after being mauled by a bear. Many were concerned that this was the end of the former slave, but Wirth has confirmed that he’ll be back for season 4.

“He survives the bear attack, but I think you will be surprised to see the manner in which he survives,” he tells “Entertainment Weekly.” “The circumstances of his survival are unique.”

There will be some new faces cropping up this year as well. If you don’t recognize Bohannon’s blushing bride, Naomi, it’s because she’s been recast. With Siobhan Williams going on to star in ABC’s drama, “Black Box,” Canadian actress MacKenzie Porter has stepped in as a replacement. Though she wasn’t Wirth’s first choice for the part, he’s got nothing but good things to say to “EW” about her performance.

“I think we were really lucky to get MacKenzie. She’s a helluva actress and has really grabbed onto this part and brought a soulfulness to it.”

Jonathan Scarfe (“Raising the Bar”), another Canadian actor, will appear in the fifth episode as Sydney Snow, an old friend of Bohannon’s from the war who’s now on the run from the law.

Another new character to look for is no-nonsense John Campbell (Jake Weber, “Medium”), whose uncompromising, law-abiding attitude will have him clashing with Bohannon. He’s been posted in Cheyenne to get a handle on Durant and the town as the railroad is being built, but his idea of order in society may prove to be a little too unyielding.

So there's definitely a lot to look forward to this season, and showrunners are excited to bring us the next chapter of “Hell on Wheels.”

“The consequences of the stories we told last year will continue to reverberate throughout the season,” said Wirth in a news release, “and fans can expect to see some shocking events that will not only change the lives of our characters, but the landscape of the series as the railroad continues its relentless march westward.”

Be sure to tune in for the season 4 premiere of this exciting period drama. “Hell on Wheels” returns to AMC Saturday, Aug. 2.