It must be the crisp mountain air that makes Boulder, Colo., (or at least its rosy-shaded incarnation in “Catch and Release”) so darn peachy. The days are filled with fishing trips or gardening. Everyone is cute, smiley, goofy and, most of all, eager to provide a comforting shoulder. People have names like “Gray” and “Fritz.” Life feels like a live-action version of a picture postcard.

It is in this world that Gray Wheeler — Jennifer Garner, in a far cry from her badass role on “Alias” — lives with her doting friends, non-existent job and winning personality. But all of this optimism and happiness somehow doesn’t make “Catch and Release” annoying; instead, it makes the film feel like life as you wish it could be — and that’s a gratifying feeling.

For the sake of full disclosure, I can hardly be objective about Garner’s performance, as I would have trouble disliking her in anything (case-in-point: I own the “Elektra” DVD). But “Catch and Release” demonstrates that no other actress plays the clumsy, cute and determined girl better than Garner: Her work in a dinner-table confession scene is incredibly endearing — the film’s best moment — and shows Garner at her romantic comedy best.

Interestingly, the film begins in the same way as Garner’s star-making series “Alias” did, with the death of her fiancé, in this case a mysterious stranger named Grady. Continuing her love affair with ABC dramas, writer and director Susannah Grant — who previous stretched her one-actress-carries-a-romantic-comedy muscles with “Erin Brokovich” — quickly borrows both her main character’s name and several plot elements from “Grey’s Anatomy;” the movie begins with Gray’s clever, quirky voiceover backed by indie music (so Meredith) and then her discovery that her fiancé actually had a secret fortune worth over a million dollars (so Denny).

Gray lives with her two male friends, fat and jolly Sammy (a decidedly un-“Clerks”-like turn for Kevin Smith) and boring Dennis. Grady’s friend from Los Angeles, Fritz, played by breakout co-star Timothy Olyphant, who looks like a cross between Johnny Depp and Barry Watson, comes to town for a while to tie up some of Grady’s loose ends. Each of the characters is handling Grady’s death in his or her own way — Gray by drinking (but only to the point where she sings country music in a charming southern accent) and obsessively painting, Sammy by cooking and casually trying to kill himself (it takes a calm admonition and a new blender to make him happy again), Dennis by sadly reminiscing and Fritz by aggressively pursuing his best friend’s grieving fiancé.

From the moment Gray catches Fritz having sex with a promiscuous caterer at Grady’s funeral, it’s only a matter of time before their chemistry turns into a relationship — after all, Boulder is the type of place where the guy always gets the girl. Gray coldly tells Fritz, “I never understood why Grady was friends with you,” but that serves as little deterrent for the determined aggressor. Only a few days later, Fritz takes pictures of Gray as she walks away from him, which is scored as a sweet moment, if you can forget the fact that his best friend, her fiancé, died a little over a week ago.

The characters do not seem to object on a moral level to Fritz’s seduction, and neither should the audience, according to Grant’s logic. Once it’s discovered that Grady had a secret love child with a blonde massage therapist named Maureen (Juliette Lewis) — who comes to Boulder with her son and becomes the best character in the movie — any notion of impropriety is supposed to be disposed.

Part of the appeal of “Catch and Release” is that it doesn’t trouble itself with complications like these — the characters act impulsively with few ramifications. The audience can’t help but be drawn in by the cast’s charm: These characters react to a suicide attempt as if a child reached into the cookie jar before dinner, and that’s OK. If only real life were so carefree.

As expected, one by one, each character discovers their true self while coming to terms with Grady’s death. “Catch and Release” feels like a cheesy Lifetime movie, but in the best possible way. It takes a significant suspension of disbelief to enjoy the quirky characters and plot twists. But once you give in, don’t be surprised if you feel an urge to hop on a plane to go fishing with friends or take a bike ride along a scenic, windy dirt road in cheery Boulder.