Is Meryl Streep a role model, or what? After watching her play Supermom in “The River Wild,” taking out a couple of bad guys, navigating rapids on a raft and saving her marriage, you wonder why she didn’t start doing action movies years ago. She makes white-water rafting look easier than going to the mat with all those accents over the years. She’s so confident-looking, so on top of everything, that you’re convinced that she’d make hamburger out of Schwarzenegger and Stallone, bake four loaves of bread and learn a few languages en route. She’s said to have done 90 percent of the stunts on the river in Montana where the film was made. You’d swear it was 100 percent. She looks strong. In fact, she’s glowing with robust health, an outdoor woman from the word splash. But first and last she’s a mom, fighting to keep her world together, not a testosterone delivery system.

In short, she’s a more highly evolved kind of slugger, from the moment we see her sculling sedately on the Charles, in contrast to what will come later. The script – which calls for her to play a river guide’s daughter who knows the ropes and returns to Montana because she’s had it with stuffy Boston and her workaholic husband, played by David Strathairn – mostly just sits there, modestly providing a pretext for Streep’s prowess. When she and her young son, played by Joseph Mazzello, are momentarily taken in by the easy charm of Kevin Bacon and his “Deliverance”-like companion, John C. Reilly, you never really worry, even after the river rats start waving guns around, reveal themselves to be escaped felons and demand that she get them through the white-water obstacle course to freedom.

It turns out that they’ve robbed a cattle auction of its proceeds and killed two men and know that the Canadian border is being watched. But messing wth Meryl is just not the way to go, even if the map tells them otherwise. Just as you knew Jack Palance could never kill Joan Crawford in “Sudden Fear,” you know Streep is a force of nature they’re never going to threaten seriously. In fact, the best parts of the film come when she laughs at them after they fall into the water. It seems right that she should do so. The fact that her seemingly wimpy husband escapes with their dog only reshuffles the deck a little; it never changes the outcome of the game.

Pro that she is, Streep goes along with the pretense that she’s endangered. But she’s much bigger than any mere felon, or river, or marital miscommunication. And it’s more fun to watch her prevail than it is Stallone or Schwarzenegger because she doesn’t just stand there exuding macho superiority. What she projects is awesome competence. Bacon at least projects initially seductive charm even if menace is impossible, given the foregone conclusion. The sterling and reliable Strathairn brings stoic dignity to the husband’s role, young Mazzello takes advantage of the chance to show more here than he did in “Jurassic Park” and Curtis Hanson’s direction is expeditious and unpretentious. But “River Wild” is a Streeporama, and Streep at the flood tide is something to see.