The Tri-States knows Mary McDonald Gershon as an actor in more than 100 productions in Dubuque and Platteville.

The film world knows Mary McDonald Gershon from two words in one of the most iconic movies of the 20th century.

Gershon, who lives in Platteville, played a member of the audience at the school board meeting in “Field of Dreams,” which is celebrating its 25th anniversary this year.

Gershon, listed by the Internet Movie Database as “PTA Heckler,” and her two words — “It’s sick!” — about the books of a controversial author comprise only one of her many roles, but undoubtedly her most famous.

“I’ve done well over 100 plays, I’m sure, mostly in Dubuque, in the Heartland Festival,” she said. “It’s on every year during All-Star Game weekend, during the World Series, during Father’s Day weekend.”

It’s safe to say that no one could have predicted how enduring “Field of Dreams” would become after its 1989 release.

“We had no idea it was going to be,” she said. “Twenty-five years later, and people still watch it. And I’ve had so many people tell me it’s their favorite movie.

“It deals with the father–son relationship and forgiveness. It deals with universal themes.”

Gershon described the three days of filming as “like a dream sequence — I couldn’t believe it was happening time after time. And they treat you like royalty.”

Gershon, one of 12 children from a Darlington family, taught for 35 years, nearly all of those at Platteville Middle School. She taught her first year in Baraboo, taught speech at UW–Platteville, and then went to PMS to teach seventh-grade English for a couple of years, or so she thought. “As it turned out, the job lasted a whole lot longer,” she said.

Gershon took an acting class in college, “and it was fun, and when I taught in my first job at Baraboo, they were doing ‘Gypsy.’ I don’t sing unless you need someone who sings badly and is not ashamed of it.”

When she moved to Platteville, Gershon started acting in the former Platteville Community Theatre. Her acting resumé includes the Grand Opera House and Bell Tower Theatre in Dubuque, as well as the former Wisconsin Shakespeare Festival at UW–Platteville and UWP’s Heartland Festival, where she played Wendy’s grandmother in “Peter Pan.”

In addition to acting in “Gypsy” in Dubuque, she played an Irish maid in the Eugene O’Neill play “Wilderness.” Other favorite parts of hers include Weezer in “Steel Magnolias,” Lenny, the oldest sister in “Crimes of the Heart,” and Aunt Abby in “Arsenic and Old Lace” in both Platteville and the Grand Opera House.

“I was in ‘Gypsy,’ and a matter of months later they bought the Grand Opera House,” she said. “I was in dozens of parts there.”

The director of the Grand Opera House, Sue Rydell, was a member of the Iowa Film Board, which was contacted about a movie to be filmed in Iowa, based on the W.P. Kinsella novel Shoeless Joe, to supply extras.

Gershon had been an extra in the movie “Miles from Home,” which starred Richard Gere as one of two brothers in a farm family who began robbing banks that were foreclosing on farms. Actor Gary Sinise made his film directing debut.

“It was fall and it was cold, and it was supposed to be a summer fair” in Gershon’s scene, she said. The scene called for a steer to be shot, and a local veterinarian was supposed to give the acting cow an anesthetic, but the anesthetic proved insufficient. The extras spent most of the night on the fair rides.

Once the producers of the baseball movie found the filming site, they sought 900 extras, “plus they had a few small speaking parts,” said Gershon. Rydell advertised and got 4,000 applicants, which were whittled down to 200 for the first audition based on “very impressive resumés, or people she knew.”

The movie’s casting director videotaped the 200. “Afterward, I thought that was fun, but that’ll be the end of that,” said Gershon. “Two days later, I got a call back — the director had picked 25 from videotape and auditioned us.”

When the director found out Gershon was a teacher, he asked her if she had ever had experience with parents opposing the teaching of any author’s books. She said she hadn’t, but some colleagues had. “I hadn’t read Shoeless Joe, and so I said Catcher in the Rye. Terence Mann is based on J.D. Salinger.”

Gershon got the role, in part because producers said she was “the epitome of an Iowa farm wife. I’ve never lived in Iowa in my entire life.”

The PTA meeting scene was shot at a school in Farley, Iowa. For each of the three days of filming — filming began the day after Platteville schools dismissed for the school year —- she drove from Platteville to a Dubuque hotel, where many cast members stayed, to be driven to Farley.

The scene was shot during the blistering summer of 1988. The gym was ventilated with barn fans, but those had to be turned off for filming. The actors would come in, film a scene and leave, and then the lights would be readjusted before the actors were brought back in.

“I can’t tell you how many times they filmed the hand-raising scene,” outtakes for which can be found on the “Field of Dreams” DVD, she said.

The PTA meeting scene included actors Kevin Costner and Amy Madigan. “Kevin Costner couldn’t have been nicer,” said Gershon. “He would play pool with the locals at night; he’d play baseball at the site when they had breaks.”

While the movie was set in Minnesota and Boston and points in between as well, most of it was filmed in this area. Scenes involving pitcher-turned-doctor Moonlight Graham were shot in Galena. A scene near Mann’s Boston apartment was shot in downtown Dubuque.

The weather complicated filming not only during the gymnasium scene. The summer of 1988 was in the middle of the Tri-State drought. “They spent a fortune on irrigating to get the corn to grow” for the baseball scenes, said Gershon.

Gershon was paid $400 each day, plus a percentage of the residuals she described as “miniscule compared to Kevin Costner’s, but I still get them.” She also got her own trailer for the three days.

One year after the film’s release, Gershon got two checks within two weeks, following film distribution deals in Italy and Japan, that were “both bigger than my monthly teaching check.” The checks allowed her to buy a new red Ford Mustang the year she retired from teaching, 14 years after the film’s release.

“I get excited every time I go to the mailbox and there’s a return address from the Screen Actors Guild,” she said. “It’s not the amount; it’s the idea.

“I think what’s amazing is the number of people who come back to the field just to play ball.”

“Field of Dreams” also became a McDonald family tradition. Each Thanksgiving, Gershon’s nieces and nephews would show their new boyfriends and girlfriends their aunt’s scene, and both of her words.

“It was a fun line,” she said. “I was very disgusted in it.”

Gershon nearly got another film part, when “The Bridges of Madison County” filmed in Iowa. She was a finalist for a waitress part, which went to a woman from Des Moines.

Gershon’s acting career has included a variety of roles, not all of them necessarily sympathetic characters.

“That’s why acting is easier than public speaking — you’re not representing yourself,” she said. “Villains are more fun because you get to say in the script what you’d never say normally.”

Gershon tutors non-English-speaking adults with Grassroots Citizens of Wisconsin in Dodgeville. She also has been dealing with health problems for several years, which have curtailed her acting.

“I used to just love playing old ladies,” she said, “until I became one.”