Peter William Siebert passed away peacefully at Emerson Hospital in Concord on Saturday, February 22, 2025. He was 70 years old.
Peter was born in Concord on November 9, 1954, to William and Anne (Sandy) Siebert, just minutes after his sister Terry. The twins joined older brothers Charlie and Tom in the family home in Conantum, the base for adventure.
Bill and Sandy didn’t just ski; every year they rented a house in the mountains for the whole winter. They didn’t just sail; they shared ownership of a classic 60-foot racing yacht. They didn’t just hike; they climbed Mount Katahdin with four young kids — Peter often described the Knife Edge from the perspective of a 6-year-old. Small sailboats were not just leisure craft; they were racing machines. As members of the Concord Sailfish Association, the family spent many summer weekends competing on lakes throughout New England. Peter and his brothers all attended Pine Island Camp in Belgrade Lakes, Maine, a family tradition spanning three generations.
Peter graduated from Concord-Carlisle High School as valedictorian in 1972. At Dartmouth College (class of 1976), he majored in Russian language and literature and went on to earn a master’s from Middlebury Language School. Along the way, he studied in the USSR on two separate occasions at the height of the Cold War. At Dartmouth, Peter nurtured a network of lifelong friends, and the college served as a staging area for their many adventures.
Dartmouth also introduced Peter to his first mainframe computer, sparking a personal and professional interest. He developed a career in IT, evolving along with the young field. In 1996, he earned a second master’s in geographic information systems from Clark University, enabling him to apply new computing tools to his personal fascination with geography and maps. Eventually Peter joined the Harvard University Planning and Development office, where he spent the last 17 years of his working life.
Peter’s true passions lay elsewhere: on oceans, mountains, country roads, hiking trails, and rocky lakeshores. Mount Washington Valley was a special place; he courted Candace there, and in 1988 the couple was married at the village church in Jackson, New Hampshire. Peter’s parents retired there, and it is where he taught his wife how to make telemark turns and his sons how to ski the edges of the trail to find the best snow. The couple sometimes took their adventures outside New England: hut-to-hut skiing in Norway and Colorado, rafting in Idaho, sailing the Caribbean, kayaking in Baja, and cycling through Tuscany.
However, Peter was destined to face challenges beyond those he set for himself. A diagnosis of polycystic kidney disease in 2000 was the beginning of a long and complex series of health crises that often defined the last 25 years of his life. Although his sister Terry offered her kidney right away, further testing revealed a tumor on his lung; instead of a transplant, Peter got a lobectomy. When his kidneys failed, he endured three years of peritoneal dialysis, a time-consuming daily process that hampered but did not stop him. He put his dialysis supplies in kayaks, carried them into lodges, and had them delivered to sailboats in the Caribbean. His son recalls Peter retrieving his high school French to explain to the ski patrol in Quebec why he needed to spend an hour in their room; one photo documents Peter lying on an island beach with a piece of driftwood serving as an IV stand.
In 2006, Peter received a new kidney from his sister and got his life back. He watched his sons race on skis and perform on stage, and he attended their high school and college graduations. Peter and his brothers purchased a 34-foot ocean-going sloop. Aboard Adelaide, Peter introduced his midwestern wife to the joys of Penobscot Bay, drawing on his extensive knowledge of its remote islands and serpentine coastline. Not long after, the couple purchased a cabin on Thompson Lake in Maine (which Peter insisted on calling a “camp”), a fresh-water exchange, Candace said, for her sailor’s salty ocean. And he finally finished building a wooden sailing dinghy — an absurdly long 14-year project which once earned the moniker Grounds for Divorce but is now a fixture on the lake named Blue Loon.
Peter contributed to the Concord community that has been home to three generations of the Siebert family. He was a member of the Concord Trails Committee for many years, mapping many of the trails in town and studying their history. He served on the board of 51 Walden Performing Arts Center, originally an historic armory that his parents had helped save and restore in the 1970s.
In 2019, Peter was diagnosed with stomach cancer and underwent a full gastrectomy, from which he never fully recovered. He was reliant on a nightly feeding tube for the rest of his life. His outdoor experience was reduced to short walks, often accompanied by his friend (the word doesn’t do it justice) Rex Morrill, who provided consistent strength, companionship, and positivity throughout his ordeal. In summer, he relished morning coffee on the dock with the sun on his face, rowing on Blue Loon, binoculars around his neck.
But last fall diabetes got its piece of Peter; in October he lost his right leg to amputation.
When he was initially diagnosed with PKD at age 50, Peter told his wife that he would be “lucky to make it to 70.” In August 2024, Peter and Candace celebrated their joint 70th birthday in the shadow of a taco truck parked on the shore of Thompson Lake, surrounded by friends and family. As Peter smuggled oysters and gin and tonics, ignoring doctor’s orders and escaping his wife’s watchful eye, it was clear to everyone that his spirit outpaced the limitations of his body.
Anyone who met Peter was struck by his helpful nature and deep, quiet intellect, punctuated by surprising moments of performative expressiveness. He remembered everything he read and often recited poetry learned in high school or called upon some tidbit of knowledge from a 40-year-old National Geographic article. He knew how everything worked and was firmly committed to the church of DIY. After she met Peter, his wife claimed that she never needed a dictionary again — she could just ask him, and he always knew the definition. Peter was known for his dry, witty humor, impeccable comedic timing, and subject matter ranging from impenetrably nerdy to shockingly raunchy.
He is survived by his wife, Candace Nelson (Concord); his sons, Luke (Bridgton, Maine) and Eli Siebert (Boston); and his three siblings Tom and his wife Betsy (Concord), Terry and her husband Tom Kuniholm (Bainbridge Island, Washington), and Ted and his wife Lana Fuller (Bainbridge Island).
Donations in Peter’s memory can be made to 51 Walden Performing Arts Center or the PKD Foundation.
A celebration of his life will be held at 11:30 a.m on April 5 at First Parish in Concord.
Arrangements under the care of Concord Funeral Home, Concord, www.concordfuneral.com.
