Trey Parker and Matt Stone make success seem effortless. Their Comedy Central show, South Park, has been a cultural sensation for 20 years, enduring four United States presidents, the rise of the streaming and 24/7 content and even the Mormon Church. It’s crude animation style and cruder humor is now beloved by multiple generations of viewers and has pulled in consistently high ratings for Comedy Central as long as its been on the air, making it the 26-year-old network’s flagship show for most of its existence. South Park’s dominance is what helped buoy Comedy Central during its early years; alongside The Daily Show, South Park is Comedy Central’s most recognizable show, winning seven Emmys and an Oscar nomination along the way.

South Park notoriously runs on break-neck, six-days-per-episode pace for producing the show and delivering episodes each week is no simple task. While other animated shows like Family Guy and The Simpsons take six months to produce an episode, South Park is famous for its rapid single-week turnaround, allowing it to comment on breaking news and ideate entire plotlines around it. Episodes are often delivered to Comedy Central hours before air time, which speaks to the trust the network has for the show’s creative team. “No one else in animation can do that,” says Mona Marshall, who has contributed voices to South Park since 2000. “They’re freaking geniuses.”

To celebrate the 20th anniversary of South Park’s August 1997 premiere, Playboy spoke with people on the South Park team about the show’s legacy and never-ending relevance.

Eliza Schneider (voice of Liane Cartman, Sharon Marsh, Principal Victoria, and various other characters from 1999-2003): South Park’s weekly schedule meant that sometimes I would come in at two a.m. on Tuesday for something that was going to broadcast on Wednesday. Often, I would be getting off playing the fiddle at an Irish pub, then catching a cab to Casa Bonita to record. When you’re in your twenties like I was, you’re not thinking, “Oh, I better be sober at two a.m. so I can go to work.” But it was exciting and a lot of fun.

Mona Marshall (voice of Sheila Broflovski, Linda Stotch, Hillary Clinton and various other characters since 2000): Even with the tight schedule, the only time South Park missed an air date was four years ago. My call time is usually 10 p.m., and I got a call from the guy who books me saying, “Don’t come down. We don’t have any power.” I think either someone hit a pole or a generator went down, but they were totally powerless and couldn’t do anything. That’s the only time they’ve missed an air date.

At South Park, everybody knows what they’re doing. No one’s having a meltdown. However, Election Night last year was interesting because the ending that had been written for that week’s show was not the ending that happened in real life. At midnight, we were waiting to record when the news came in. And we didn’t have Hillary Clinton, whose voice I do on the show. We had another president. So they sent us home to come back at seven a.m. the next day, on the air date, so that we could record a different ending.

On the one hand, it’s a very well-oiled machine, and people really know what they’re doing. But on the other hand, if they’re thrown a curve, they seem to really know what to do with it. They’re freaking geniuses.

Nancy Pimental (a South Park writer during the early years, from 1998-2001, now an executive producer for Showtime’s Shameless): In some ways, the chaos was the well-oiled machine. It was a well-oiled machine that operated within a very short window of time. I’m the kind of writer who works better under pressure, and that was the culture at South Park where the best work was done with the ticking time clock. That also kept the show super current.

Schneider: It was all hands on deck to get episodes out by the next day. It’s an incredibly unique work style. If you think about The Simpsons, they take nine months to create an episode. South Park is more similar to Saturday Night Live, I imagine. It’s all hands on deck, you only have a week and you don’t see your family for certain parts of the week. But you feel like you’re doing something really pertinent, relevant and revolutionary.

Marshall: Saturday Night Live is a great comparison.

Pimental: SNL is kind of a cool analogy. I agree with that, to a degree. As far as skewering or satirizing whatever topic and events happened that week, we were definitely able to do that like Saturday Night Live.

PewDiePie (YouTuber who was one of South Park’s rare guest voices for multiple episodes): Before I did the show, I basically just knew the general concept of the episode. Things changed a lot during the few days that it went in. I knew about their “on the fly” schedule that they have, but I had no idea how intense it actually was. Experiencing it first-hand was crazy. I’m super impressed with how they actually make it happen.

Schneider: Trey is the creative genius. He’s brilliant on so many levels. I feel like he was the creative driving force. In whatever room I went into, I’d often see Trey doing the job of an editor, writer or songwriter. He really had his hand in all of the creative stuff. In a sense, it kind of felt like a one-man show, in that regard.

Marshall: There are times when I hear Trey do a voice and I’ll just think, “Oh my God, where did that come from?”

Schneider: I remember we took a bus to a boat party we had one year, and I sat next to Trey on the bus ride. He had the entire bus in stitches doing this totally unintelligible Japanese voice. His comedic voice is pure genius. Matt is very funny too, and he also did a lot of the voices on the show. I saw him as more of the liaison between Trey and the rest of the world. I actually had a huge crush on Matt, by the way. The whole Jew fro and the gap between the teeth really did it for me. I had to stay far away from Matt [laughs].

Tommy Chong (one of the show’s rare high-profile guest stars, in the Season 4 episode “Cherokee Hair Tampons”): When I met the Matt and Trey—oh my god. It was like I’d known them forever. That sense of humor they’ve got—it’s changed the world.

PewDiePie: Working directly with Matt and Trey was unreal. That’s the only way to describe my experience on the show. I still can’t believe it sometimes when I think about it. I loved it. And the fact that after all these years they are still working passionately on the show is a huge inspiration to me.

Pimental: Matt and Trey both had a similar sense of humor, and they were very much on the same page in their sensibilities in storytelling. They were a yin and yang and they complemented each other. Trey could hole himself up in the edit bay for hours at a time and disconnect from people to actually get the show ready. Matt would be on the phone dealing with Comedy Central, maybe fighting with them about censorship. Matt maybe added more of a business voice and was more the person who would fight the battles of what we were doing, and Trey would be executing the results of that battle.

Schneider: I remember hearing Matt on the phone with Comedy Central’s Standards and Practices about my Fingerbang song from Season 4. I think that was the first song on the radio to get away with using as many swear words as it did [laughs].

Marshall: It is adolescent humor if you look at it on the outside. But I think there are a few levels to why the show resonates with people so much. Remember Rocky and Bullwinkle? That show worked on multiple levels, as it was fun and amusing for children yet they skewered everybody. South Park does the same thing. There’s this brilliant skewering of hypocrisy in everything. That’s why South Park has the range of appeal that it has, and that’s why it’s been meaningful for 20 years.

The way the show is set up allows them to be very topical. There’s no one else in animation who can do that. The Simpsons can’t do that.

Schneider: I remember the Elián González episode with Janet Reno. It was Easter, the raid happened that weekend and an episode about it aired on that Wednesday. For animation that’s unheard of. South Park strikes an incredible balance between making people laugh and informing people about shit that’s going on around the world. It was exciting to be part of the zeitgeist, in a sense.

PewDiePie: As a kid, I loved South Park for the fart jokes. As an adult, I love South Park for the social commentary…and the fart jokes.

Chong: South Park touches on every aspect of human life. But it’s all seen through the eyes of these kids who are innocent. When you come at a subject through the eyes of children, everything becomes very clear. It knocks the whole human experience down to an age where it’s all really easy to understand. And that’s why they’re so popular. That’s why they can attack any subject whatsoever. When you approach things from that point of view—pure innocence—you get away with so much. They’re geniuses for that.

Schneider: We had some pretty awesome parties. I couldn’t keep up with those guys (laughs). It was definitely a fraternity vibe. There was a lot of hazing going on. I remember one time they peed on [animation director] Eric Stough’s motorcycle. I used to joke that it was kind of like working with seventh graders. Gwyneth Paltrow said that you stop maturing when you become famous because everything is taken care of for you.

There are some rumors I could tell you, but these are rumors. I heard a rumor that you could tell whether an episode of South Park was more of a “mushrooms episode” or a “weed episode” based on what kind of aliens were involved in the storyline that week. I assumed Lemmiwinks was a mushrooms episode. But these are vague memories I have.

In 1999, in South Park’s third season, voice actor Mary Kay Bergman took her own life. Bergman was the only one of the only actors who provided voices on the show, aside from Matt Stone and Trey Parker. She voiced most of the female characters on South Park’s first three seasons and the 1999 movie South Park: Bigger Longer and Uncut. Her death was a devastating blow to the South Park team and to the voice actor community.

Schneider: I was shocked when Mary Kay Bergman passed away. It was devastating. I had so much reverence for her. The show was in a pickle because they lost the whole female population of their world. And they were mid-season. When I joined the show to try to voice her characters, within a week I had to match eight different voices that Mary Kay Bergman had done. My theory is that Mary Kay was a somewhat self-destructive person. What she was doing with her voice to create the Mrs. Crabtree character was impossible to replicate without injuring my voice.

Marshall: I still kind of tear up talking about this. Mary Kay was always very, very generous. She was the kind of actress who’d say, “Hey, I’m going out for this role. You’d be really good, too. Get your agent to get you in.” In the summer of 1999, Mary Kay and I were sitting next to each other at a benefit event and she was just wonderful. And then in November, she killed herself. And the word went out that South Park had to replace her voices. I would have to listen to her voice over and over again on CDs. What kept me going was what Mary Kay used to say, “Mona, I’m not available to do this role, but you’d be really good. So go ahead.”

The first few years were very hard. Mary Kay was a light. People adored this woman. She remembered everybody’s birthday with a card. I felt I had very big shoes to fill. Every time November rolls around I just think about her.

This show, after 20 years, is into a second generation. Think of the people who enjoyed it in their teens. Twenty years later, they have children who are in their teens watching the show. Who knows how long it can go on.

Schneider: The show can last as long as they want it to. If anyone can keep it fresh, Trey and Matt can.