Helen Carpenter
Helen is the novel's protagonist and narrator. At thirty-two, Helen is an elementary school teacher living in Boston. Center depicts Helen as well-organized and helpful, but simultaneously cynical and resentful. She is estranged from her mother and father, having been raised by her grandmother, GiGi, in Evanston, Illinois. One year before the novel begins, Helen miscarried her first child; when her husband, Mike, wasn't there to comfort her because he was out drinking, Helen asked for a divorce. Seeking to challenge herself and defy other people's expectations, Helen signs up for a three-week outdoor survival course in Wyoming. Unbeknownst to Helen, her brother Duncan's best friend, Jake, is also taking the course. Torn between an attraction to Jake and irritation that he is disrupting her plans, Helen seeks to distance herself from him and do her best to acquire survival skills and exceed their instructor's low expectations of her. By the end of the novel, Helen realizes she is in love with Jake, who has been in love with her since the day he first saw her. She also works through the trauma of feeling responsible for her brother Nathan's death, which occurred when they were both children.
Jake Archer
The primary antagonist of the book, Jake is the best friend and roommate of Helen's younger brother, Duncan. Although Helen has always overlooked the 22-year-old Jake, automatically assuming he is just as irresponsible and degenerate as her brother, Jake surprises Helen with his wit, emotional intelligence, strength, and ingenuity. While Jake has loved Helen since the day he met her, on their road trip from Boston to Wyoming, he puts a stop to their growing intimacy and claims she needs a man less selfish than he or her ex. Later in the book, Jake admits that he recently learned he has an incurable condition that will soon cause him to lose his eyesight completely. He feels guilty for pursuing Helen when he knows he will be reliant on whoever he is with. However, Helen accepts Jake for who he is, not seeing his condition as equivalent to her ex-husband's alcoholism.
Duncan Carpenter
Duncan is Helen's younger brother. At twenty-two, Duncan has just finished college with no job prospects and lives in a trashy apartment with Jake. Resented by his sister, Duncan hopes to get in Helen's good graces by taking care of her dog while she is hiking in Wyoming. However, Duncan takes the dog into his care only for her to die in his arms. Toward the end of the novel, he brings the dog to Helen at their grandmother's house so they can bury the dog in the yard. When Helen realizes her resentment toward Duncan relates to her guilt over Nathan's death and the feeling that Duncan is to blame for their parents' separation, Helen learns to forgive Duncan and appreciate him for the fun-loving, well-intention person he is.
Grandma GiGi
GiGi is Helen’s and Duncan’s grandmother. In her mid-eighties, GiGi is spirited and independent, living alone in the Evanston house where she raised Helen and Duncan when their mother couldn't cope. She is a portrait painter. After Helen returns from her hiking trip, GiGi discusses what really happened when Helen and Duncan came to live with her. While Helen had believed her mother abandoned her children, in fact she was so emotionally fragile and mentally ill that GiGi insisted on raising the kids herself, knowing they would be better off with her. A perceptive person, GiGi has known for years that Jake is in love with Helen.
Helen and Duncan's Mother
Helen and Duncan's mother is the daughter of Grandma GiGi. When her son Nathan died in a drowning accident as a child, Helen's mother immediately got pregnant with Duncan. In Helen's opinion, this rash decision was meant to forestall her grief. However, introducing a new baby while she was grieving led to Helen's mother's relationship with her husband deteriorating quickly. When Helen and Duncan were children, their mother attempted suicide. After that, GiGi raised the kids.
Pickle
Pickle is Helen's rescue dog—a mini dachshund. A balding "ankle biter," Pickle is distrustful of most people, having been abused by former owners. Although Helen's attitude toward Pickle is tinged with resentment, she loves her dog, who has often been the only supportive force in her life in the last year. While being cared for by Duncan, Pickle dies from a gas bubble getting trapped in her intestines. She is buried in GiGi's backyard near Lambchop, Helen's and Duncan's childhood dog.
Windy
Windy is a hiker in Helen's tent group. A blond and conventionally attractive Californian, Windy earns the nickname Heartbreaker because all the men on the trip desire her. While Helen initially dislikes Windy for being naturally athletic, irritatingly earnest, and transparently privileged, she learns to appreciate Windy's insights about positive psychology, appreciation, and how Helen should view her dog's moodiness. However, Windy develops a crush on Jake, leading Helen to make unfavorable comparisons between herself and Windy. While Windy believes she and Jake will be together, at the end of the book, Jake reveals he turned Windy down because he is in love with Helen.
Beckett
Beckett is the BCSC course instructor who leads Helen's group on a three-week hike in the Absaroka Range. Young-looking, Beckett compensates for the lack of authority associated with his youth by deepening his voice and treating his participants with mockery and belittling comments. However, Helen and the other participants develop respect for Beckett, appreciating his knowledge and the reverence he has for nature. At the end of the course, Beckett votes for Helen to receive a Certificate of Merit.
Hugh
Hugh is a fellow hiker on Helen's trip. Feeling like he doesn't belong with the rest of the college-student hikers, Hugh befriends Helen, making friends with her by poking fun at the others. Hugh ignores Beckett's warning not to step on fallen logs, and breaks through one, falling so hard that his hip fractures and dislocates. Helen and the group spend an entire day carrying Hugh out of the forest on a makeshift stretcher so he can be evacuated to a hospital. Hugh receives one of the group's Certificates of Merit at the end of the trip.
Mike Dull
Mike is Helen's ex-husband. An alcoholic, Mike was notoriously unreliable during his five-year marriage to Helen. Although in recovery now, Mike calls Helen, testing her emotional boundaries and seeking support from her when he nearly relapses. The night before her hike starts, Mike attempts to convince Helen that she shouldn't go on the trip, inviting her to get back together with him instead. Helen eventually learns to stop picking up when he calls.
