A few Christmases ago, Maria Walker and her son Tai, now 5, went to see "The Polar Express." Halfway through the animated Tom Hanks film, they left the theater.

"It wasn't an upbeat Christmas movie, and I could tell he was bored," the Twin Falls woman said.

Walker isn't alone in her struggle to find films she considers appropriate for children. Across Magic Valley, parents eye the movie listings and have to make a choice: Do they rely on word of mouth, critics' reviews or detailed ratings before giving Junior the OK?

That decision is harder when theaters are full of sex and violence. Hollywood is turning out lots of PG-13 and R-rated movies, and fewer rated G or PG.

"I've been wanting to take (my son) to a movie for the last month or so but there isn't anything out there I would take him to see," Walker said. The selection isn't a problem for teens or adults, she added. "For the size of the town that we are, there's enough of a variance in the type of movies that they show."

Theaters in south-central Idaho are currently playing five PG-rated movies and one G-rated film ("Mr. Magorium's Wonder Emporium"); the remaining 19 are rated PG-13 or R. Interstate Amusement managing director Larry Roper, who buys movies for the theaters in Twin Falls and Jerome, said this proportion is directly linked to the proportion released by movie studios.

"You can't make the mix. You just play what's available," he said. As each week's releases are offered to theaters, Roper looks at the receipts for the previous week's movies; the lowest grossing are replaced by new releases.

"The studios just make pictures and they set their opening dates. If they decide to take so many runs of the picture, Twin Falls falls into that category and we open," he said. Movies with limited initial release - such as "Juno" or "No Country for Old Men" - often are made available to smaller markets like Twin Falls weeks or months after their release in big cities. "We usually end up picking them up."

Roper said the Interstate Amusement theaters tend to run more independent and foreign films than theaters in other markets of similar size, a variety appreciated by Shauna Fowler of Twin Falls.

"We just moved back up here from Rupert, so there's 10 times more movie options," Fowler said. She and her husband see films with restrictive ratings like "Cloverfield" and "The Bourne Ultimatum," but they're more cautious about what they take their 8-year-old and 4-year-old children to.

"As long as it has a PG rating or is a cartoon we're not too concerned about it," she said. "If we're not sure, then we don't take them."

The Fowler kids sometimes see trailers for films on television or hear about them and ask if they can see the movie. Recently, they wanted to see "Good Luck Chuck," a comedy rated R for sequences of strong sexual content, crude language, nudity and drug use. Most trailers for the movie featured fairly tame comedic moments.

"We've seen it, but we wouldn't let the kids watch it," Fowler said. "We try to avoid the raunchy ones."

A letter is just a letter, and not terribly informative. But reasons for the ratings are available on Web sites like that of the Motion Picture Association of America, on cards handed out at many movie theaters on request, in some movie advertising and elsewhere.

"I think the rating system describes exactly what they're going to get into. It's informative, it works, it does its purpose," Roper said.

At the Shoshone Showhouse, owners Gayla and Terry Zech go a bit further to limit what they offer their patrons - but that's what the patrons seem to want.

"We have done a couple R-rated movies in the past that we thought were really epic films, like 'Gladiator,' and we do really poorly with them," Terry Zech said. People ask why he doesn't show films with more restrictive ratings. "And we say, 'Well, we just don't think it's appropriate for our audience.'"

The Zechs even censored a movie once. Before patrons paid to see "Titanic," the staff warned them that the nude scene would be visually blocked. There were no complaints, Zech said, and a few compliments for making parents more comfortable bringing their children to the blockbuster.

The Shoshone theater shows mostly films rated G and PG, with an occasional PG-13 thrown in if the Zechs think it would be appropriate for families. One example of a PG-13 film they recently rejected was "Blades of Glory," a Will Ferrell comedy.

"We elected not to show it because we thought it was a little off. Any time it's questionable we decide not to show them," Zech said. "Our feeling is, the rating system, I'm often offended more by PG-13 than R. They allow some nudity, bad language, sexual scenes that I don't think are appropriate. R's are usually violence."

Because of the theater's size and its audience, the Showhouse usually gets films weeks or months after their wider open. For the Zechs, this is a good thing, because it allows positive word of mouth to grow about the family films they feature - like "Bee Movie," "Enchanted" and "National Treasure: Book of Secrets," which they have scheduled to appear in coming weeks.

"Unless it's been a popular movie and done well, we don't get people out," Zech said. "There's not enough good movies, to be honest. We're pretty picky."

During the coldest months, the theater often doesn't open at all because the heating costs would outweigh its profits. And at other times of year, a week or more goes by between movies if there is nothing available that the Zechs think would appeal to their southern Idaho audience.

Ariel Hansen may be reached at ariel.hansen@lee.net or 735-3376.

For local movie offerings: • Twin Cinema 12 (734-2400), The Orpheum (Twin Falls, 733-5570), The Odyssey (Twin Falls, 736-8369), Jerome Cinema (324-8875): movies.magicvalley.com • Century Cinema (Burley, 678-7142) and Burley Theatre (678-5631): centurycinemas5.com • Bigwood 4 Cinemas (Hailey, 578-0971) and Ski Time 2 Cinemas (Ketchum, 726-1039): metrorockymountain.com • Magic Lantern (Ketchum, 726-4274): store.magiclanterncinemas.com/index.html • Sun Valley Opera House (622-2244): Sunvalley.com/SunValley/ info/act.ent.moh.aspx • Shoshone Showhouse (886-2332): no Web site