The “Little House on the Prairie” set was filled with drinking, smoking and “insane” parties, according to former star Alison Arngrim.

Arngrim, who played child bully Nellie Oleson in the iconic TV series, said on the “Here’s What Happened” podcast last week the show’s “older” crew members acted like the characters from “Mad Men.”

“They came from an era where everybody smoked and everybody drank, like all the time,” the actress explained. “There was no health food and no vegetarian options and gluten-free muffins.”

She added, “The prop men were in charge of the booze and the cigarettes, as well as the candy, so everyone was hanging out at their truck.”

Arngrim, now 64, clarified that none of the child actors were smoking on the set.

But some of her adult co-stars, including Michael Landon, “were puffing Marlboros all over the place” with the crew, who she said “went through a couple cases” of beer every day.

Arngrim also claimed Landon, who played the show’s patriarch, Charles Ingalls, “often would have a shot of whatever he was drinking that day” — usually whiskey.

Despite that, Arngrim insisted “no one was drunk on the set.”

“They were burning it off or something, because these guys were going on ladders and hanging lights and I’m going, ‘I know they’re living on beer,’” she shared.

Arngrim also said when the crew was “running low” on beer, they’d send somebody out to restock.

“The prop truck had a whole bar and at the end of each day when they were done they’d put up like a bar with a board on a couple of saw horses and then start really drinking,” she recalled.

The crew, according to Arngrim, also had “insane” Christmas and wrap parties that involved everyone having a designated driver.

Arngrim said she couldn’t believe the crew members were “still awake” to party after such heavy drinking.

“Their tolerance was God knows what,” she shared. “Because they were out of the ’50s where you drank and you smoked. They did not think this was weird.”

Based on the popular book series by Laura Ingalls Wilder, “Little House on the Prairie” followed the pioneer Ingalls family living their rural frontier life in Walnut Grove, Minnesota. 

The series, which aired for nine seasons between 1974 and 1983 on NBC, had multiple scandals including Landon’s affair with teenage stand-in actress Cindy Clerico and stars Melissa Gilbert and Melissa Sue Anderson’s decades-long feud.

A “Little House on the Prairie” reboot series with a new cast premiered on Netflix last week.