“Outsiders” offers David Morse a work setting as far removed from “Treme” as can be.

In the post-Katrina HBO drama, Morse played NOPD Lt. Terry Colson. In the WGN America drama “Outsiders,” debuting at 8 p.m. Tuesday, Morse plays Big Foster, a hardened elder of a hilltop clan that lives mostly off the grid until mining interests attempt to force him and his people off the land they’ve occupied for generations.

Tensions between the isolated Farrell tribe and down-mountain townies drive the story into overdrive when possible eviction enters the plot, but the internal tribal politics of the occupying Farrells, with Big Foster at the center, are equally heated.

Morse’s notable roles between Colson and Big Foster include a small role playing a new-age guru in the second season of HBO’s “True Detective” and a moving turn as damaged pro football star Mike Webster in the film “Concussion.”

Morse’s prep for “Outsiders” included reading Shakespeare “just to get a sense of the language,” he said, as well as studying video links to documentaries distributed to cast members by Peter Mattei, the show’s creator and executive producer.

Mattei researched Native American and Amazonian cultures in preparing the series, among other isolated clans, including those that populated the same backcountry Appalachian setting as the Farrell colony.

The documentaries were useful in “helping us get a feel for the world — the language, the dancing, the music,” Morse said. “There really were Scotch-Irish people who at the time of the American Revolution disappeared into the mountains.

There are a lot of people there who are descendants of these real people.

“There has been a lot of Native American interaction over the centuries, and we paid attention to that.

“We had to take all that and make it our own world.”

The “Outsiders” cast also includes Ryan Hurst (”Sons of Anarchy”), Gillian Alexy (“Royal Pains”), Thomas M. Wright (“Top of the Lake”), Kyle Gallner (“Smallville”) and Christina Jackson (“Boardwalk Empire”). In addition to Mattei, executive producers include Peter Tolan (“Rescue Me”) and actor Paul Giamatti, whose involvement comes through his production company, Touchy Feely Films. (“I don’t get to play badass guys riding ATVs a whole hell of a lot, but I do like watching that kind of thing,” he said.)

In the series’ initial scripts, Big Foster was “just a bad guy … a bully … a pig,” Morse said. As filming commenced on location near Pittsburgh, there was “a process of discovery about really who he was and what his motivation is in this world,” Morse said.

Morse and other cast members worked with Mattei to better flesh out their characters as filming proceeded. As the series opens, Big Foster is in line behind his mother to lead the Farrell clan.

“He’s a guy who was never allowed to be fully himself, and he’s just been rotting, basically, for a long time, drinking and partying and being kind of whatever he wants to be until he gets to be in power, which has been kept from him by his mother,” Morse said. “But at the same time, he senses a threat from the world below.

“He’s a man who really does love their way of life and feels a deep threat to what they’ve kept together and created together for a long time. So a lot of what he does comes out of that.”

The production used locals as background actors for scenes in the Farrell settlement, and interaction with them helped the cast acclimate. Alexy and Morse said their first big group scenes among the local were illuminating.

“Many of them had never done this before,” she said of the local background extras. “Most of them required very little hair-and-makeup. They came as they were. They put them in costumes and put them on those sets. We came in and they said, ‘Hello, here’s our world.’ It was very empowering and very exciting.”

Morse said some of his earliest scenes to shoot had Big Foster commanding a large room of those background characters.

“Seeing the background people and how much they’d invested in the world — they’d never read a script, and didn’t know anything about it — (was) very touching in a lot of ways,” Morse said.

Mattei credited Morse with giving Big Foster more than one dimension.

“He’s such a sweet and thoughtful man, and so he had a lot of input in terms of the character, and I think had a great deal to do (with making) that character’s journey more sympathetic,” Mattei said. “The part of Big Foster on the page can come across as a sort of an over-the-top villain-type character. It’s always good to cast a little bit against type. David bringing that humanity and intelligence to the role was really important.”