To outside observers — even her brother — Donna Marie Burns Anderson was doing OK.

She had a thriving career as an ob-gyn and had returned to practice at Regions Hospital in St. Paul after a messy divorce out in California.

By 2001, though, colleagues and family began to notice she'd become paranoid and delusional. Those delusions culminated in 2002 when she stabbed to death her 13-year-old son.

Anderson's brother, Lakeville City Council Member Doug Anderson, doesn't often talk publicly about such personal matters. But he's sharing his sister's story because she is the catalyst for a hefty physical challenge he'll take on starting next month.

Anderson, who turns 60 in August, plans to join his close friend Tom Mork and two others on a 2,100-mile bike ride up the Mississippi River, from Venice, La., to Lake Itasca in northern Minnesota.

The goal of Tom's Big Ride, as it's dubbed, is to raise at least $100,000 for NAMI, the National Alliance of Mental Illness.

Their hope, Anderson said, is "to help people become aware that it's OK to talk about mental health issues. It's OK to seek help. You don't need to experience some of the things Tom's family or my family has experienced."

Mork's family, too, has struggled with mental illness. His daughter, Christine, was diagnosed as bipolar after years of rebellion, anger and dangerous decisions.

Tom's Big Ride starts July 6. Although only four men plan to ride the entire route, about 18 others — spouses, children, friends, colleagues — will join them for parts of the journey. Each rider has to raise at least $1,000 in donations.

They will pedal south to north "to emphasize our tagline of 'pedaling the uphill battle for mental illness," Mork said on his website, www.tomsbigride.org. "For those struggling with mental illness, every day is an uphill battle. Our climb is a modest one in comparison."

They'll cover about 72 miles a day, followed by a support vehicle, but also take a few one- or two-day breaks along the way. The ride will conclude Aug. 13 at the headwaters of the Mississippi.

Helping a daughter

Mork said he rediscovered his childhood love of bike riding while navigating through his daughter's troubles. Time on the bike gave his mind time to relax.

Tom's Big Ride "started as a bucket list, but it's really evolved from that," Mork said last week. "Our goal is really geared to peeling away the layers of the stigma surrounding mental illness."

Mork, who turns 60 on one of the last stages of the ride, is founder and president of Lakeview Bank in Lakeville.

"I have a very gracious and understanding board of directors," he said. "A number of us are getting a little long in the tooth. This is a great opportunity for us to test our management succession plan."

Mork's daughter Christine, now 26, became more angry and withdrawn during her last two years of high school and during her college years spent in California.

That anger became rage in March 2010 when she admitted to her parents that she'd married a 35-year-old felon with a heroin habit. Christine wanted out; Mork said he reacted poorly and Christine fled. A psychiatric hospitalization came after she admitted she was suicidal.

"Christine is doing very well," Mork said of his family's current situation. "She's working full time. She lives at home with us. That's been good. We can kind of keep an eye on her. She has done a marvelous job of sticking to her medication, seeing her therapist and just generally maturing."

Forgiving a sister

Anderson retired last fall as chief financial officer at Hamline University. He has served on the Lakeville City Council since Jan. 1, 2013.

His sister, Donna Anderson, was a high achiever even as a high schooler. She went to Stanford University and studied in Tanzania with anthropologist Jane Goodall.

She had a successful career as an ob-gyn for women with high-risk pregnancies. She married, had a son and then moved back to the Twin Cities in 1997.

She told a friend in February 2002 that she'd quit her job at Regions because the hospital wanted her to murder someone. Later that month, she traveled from her home in Shoreview to Burlingame, Calif., where her 13-year-old son, Stephen, was visiting his grandparents.

She stabbed the boy to death and assaulted her ex-husband when he tried to intervene.

Once Anderson was deemed competent to stand trial, she fired her attorney and pleaded guilty, ending the case without a trial or an explanation for her actions.

Doug Anderson visits his sister, who is serving a life sentence, annually.

"It's a bit hard for me to talk about," he said. "Part of it is that it's difficult to understand as a person that doesn't have mental illness.

"I've gone through the process of forgiveness and reconciliation. My sister has been becoming a very contributing member of the community she has to live in. So it's really more, instead of a story of tragedy, more of forgiveness, reconciliation and hope."

People can find out more about Tom's Big Ride or make a donation by visiting the website: www.tomsbigride.org.