Peter Wessel Birkeland died of natural causes in Boulder, Colorado on January 25, 2022, a snowy day befitting a lifelong skier.  He was born in Seattle, Washington, on September 19, 1934, to Norwegian immigrant Ivar Wessel Birkeland and Marguerite Ellen O’Conner Birkeland of Rochester, Minnesota.  He married Suzanne Franzke, also from Seattle, in August 1959.  Pete and Sue’s unconditional love for each other never waned, and they were nearly inseparable for more than 60 years.

He grew up attending the greater Seattle school system, graduating from Bellevue High School.  In 1958, he graduated from the University of Washington in Geology, and in 1961 he completed a Ph.D. in Geology from Stanford University.  He served in the U.S. Army from 1953–1955, ending his service as a ski trooper in the Mountain and Cold Weather Training Command at Camp Hale in Colorado.

Pete’s professional career began as a professor at the University of California – Berkeley.  In 1967, he took a position at the University of Colorado – Boulder, where he did research and taught in the combined fields of soils and geology until his retirement.  Throughout his career, he traveled the western United States and the world with his wife and children studying soils in environments ranging from mountains to deserts to the tropics.  He received several national awards for his research and teaching, and authored a successful introductory geology textbook, Putnam’s Geology, with his colleague Ed Larson.  In addition, he authored three editions of a book on Soils Geomorphology, a subfield of Geology he helped pioneer.  Pete’s proudest professional accomplishment was his mentoring and training of many successful students in this field.  Those students went on to become both his colleagues and his cherished friends, and he stayed in touch with them long after he retired.

Pete was a lifelong skier, from the age of two to the age of 85.  In high school he competed in all events (cross country, downhill, and ski jumping) in the Seattle ski league, which is where he first met Suzanne.  He later raced for the U.S. Army at Camp Hale and for the University of Washington.  The high point of his racing career was two NCAA silver medals in alpine skiing in 1956, one in the Downhill and one in the Alpine Combined (slalom and downhill combined).  When the family moved to Colorado in 1967, they backcountry skied (on wooden cross-country skis) throughout the Front Range, and downhill skied at ski areas across the state almost every weekend.

Another thing Pete loved was riding his bike.  He rarely used his car except to go to the mountains, and he enjoyed encouraging others to bike.  He and Suzanne did numerous international bike trips with family and friends.  These included using bikes to do geology fieldwork while traveling around the world in 1984-85, biking down the Danube River in 1994, and biking in the Spanish Pyrenees in 1996.  In 2005, he and Suzanne and their friends biked in France and re-traced some of the classic stages of the Tour de France, an event he enjoyed watching on TV.

Not surprisingly, his retirement years involved geology, skiing, biking, and time in the mountains. He joined friends and former students to put on local geology field trips for national and international meetings, as well as for visiting students and professors.  He volunteered for the Colorado Mountain Club, teaching backcountry skiing, making maps, and leading ski and hiking trips.  When not skiing he enjoyed riding his bike and hiking in the mountains with Suzanne and their friends.

Though he had numerous professional and personal accomplishments, Pete’s biggest passion was for people.  He made many lifetime friends, and he cherished and nurtured those friendships out on the trails and over a beer or two.  His love for Sue lasted over 60 years and never waned.  He was incredibly engaged and supportive of the directions his children chose in life.  In his later years he especially enjoyed his time with his three grandchildren, including hiking and skiing with them, and loved to hear about their adventures.  Another hobby he took up late in life was drawing.  Dubbing himself “Petecasso”, he enjoyed drawing cubist-inspired pictures and humorous cartoons for family, friends, and neighbors.

He is survived by his wife Suzanne, son Karl (daughter-in-law Ginger and grandchildren Erika and Kelsey) of Bozeman, Montana, and daughter Robin (son-in-law John Jugl and grandchild Natasha) of Boulder.  He was predeceased by his parents and his three siblings (Ivar “Buzzy” Birkeland, Jr., Sally Burklund, and Fred Birkeland).  He loved his family greatly and was a wonderful husband, father, brother, and uncle.  He relished his role as a grandfather and enjoyed engaging with his grandchildren on their level, whether that involved drawing funny pictures, joking around with them, being childish and goofy, and attending important events in their lives.

His final year of life was not an easy one, but he never complained.  Pete took on the challenges of aging with grace and humility, and his innate inner kindness.  He was visited frequently by his many friends and colleagues, who provided a great deal of support and love.  We are particularly thankful for the kindness and care he received from everyone at hospice and from his caregivers.  His children also would like to acknowledge the amazing support that he and Suzanne received during this time by their many friends and their incredible neighbors.

His primary concern later in life was for the future of our planet for his children, grandchildren, and all future generations.  Contributions in his memory can be made to Earthjustice (

A memorial service will be held in Boulder at a later date when it is safe to gather, likely in late-spring or early-summer.

16 thoughts on “Peter Wessel Birkeland”

  1. Pete was an amazing advisor, geologist, and friend. He skied into my field area in Rocky Mountain National Park and went above and beyond to edit my writing thoroughly. He read everything! I have loved visiting their home over the years, and count myself lucky to know the Birkelands.

    Very Best Regards, and virtual hugs to Sue,

  2. To: Karl, Robin, and Sue. Pete was a ‘breath of fresh air’ to me and many more students and colleagues. Who else would spend three days checking my thesis sites in the mountains, all with numerous discussions of my findings and how they might relate to the wider field, a dry run for my thesis defence in the coming weeks of 1970. Pete was a penultimate professor at the University of Colorado, serving with many others–giants in their relative fields–part of a department unlike many others I’ve worked in. Geology at Colorado–Undergrads to full profs–all on a first name basis, no pomp allowed, research blended smoothly into teaching, classes sparked up with major efforts in various fields. I treasured one course–Quaternary Stratigraphy– so much that I even remember the course number (540), something Pete could hardly believe, when I mentioned it just prior to his retirement party in 97. Pete treasured his students–undergrads to Ph.D’s–and his colleagues like few others, almost as much as dry powder and steep slopes, or the next site to explore. As my career took off, I turned out papers that Pete read, his comments piquing points here and there, often reminding me of my thesis– chapters handed in on Friday, back on Monday fully critiqued–and of various field sites and trips of past times. Among the field sites, Degge Arroyo looms in my mind, digging on Sundays–Pete, Karl (age ~10), Netoff, Marcos and me. Pete was one prof from the old days that I stayed in touch with throughout my career. I will miss him, greatly!
    Bill Mahaney, Toronto

  3. We met on a GSA tour of the Upper Truckee River Basin that Pete led in early 1966 and have been friends and professional colleagues ever since. Pete played a major role in the success of my own geological career in so many ways that I can’t begin to acknowledge. With heartfelt condolences to Sue, Karl and Robin for the earthly loss of such a truly awesome soulmate and father.

  4. Even though I did not know Pete well, I liked him a lot. He was always friendly and kind to me and I learned from him on field trips that he led. What I DID know well were many of his students. Numerous times, I would discover that a Quaternary scientist who had impressed me with the depth and quality of his or her work, turned out to be a “Birkeland student.” Much of the meaningful work on the Quaternary deposits of the western U.S. was done by disciples of Pete. He leaves a lasting legacy.

  5. Pete joined the CU faculty shortly after I departed with my MS (1962), but I followed his work closely for years. His legacy is apparent, and strong. We know more about Earth because of Pete’s intelligence, imagination, generosity, and hard work.

    Bob Giegengack

  6. I met Pete during my first semester as a graduate student in September of 1985. What a breath of fresh air he was every day. Most of the faculty were stultifyingly serious, whereas Pete nearly always used some uplifting colorful vocabulary to make me and other students comfortable. I still appreciate that about him. One of the finest presentations I have ever attended was his “Around the World in 80 Soils.” His and Sue’s verve inspire not only their children and grandchildren, but all those legions of students and it brings to them a love of our earth and being out-of-doors. I am lucky to count among my dear friends, his son, Karl and daughter-in-law, Ginger. Their verve is now inspiring their children and yet more legions of students to love our earth and to get outside.
    Thanks, Pete. You are loved and missed.
    Don Friend, Mankato

  7. I can’t remember when I first met Pete, but it was at least 40 years ago. I ran into him at numerous Friends of the Pleistocene, QG&G receptions, seminars, etc. over the years. I always admired him for his unmatchable knowledge of Quaternary soils and for his openness and modesty. He was always a pleasure to be around. I was delighted when he was given the Kirk Bryan Award. He was a true leader and a fine human being. May he rest in peace.

  8. Very sad to hear about Pete’s passing, and I hope that his family can eventually find peace. I just grabbed his ‘soils and geomorphology’ textbook off my shelf that I bought as an undergraduate student. Doing that brings me back to describing soils along mountain roads outside of Boulder and Pete going for a run and letting us figure it out. I appreciated his style and won’t forget it. Pete, you will be missed but your love of soil lives in all of those that had a pleasure of learning from you.

  9. Pete was a wonderful man. He had a smile for everyone and his enthusiasm for life was infectious. What a joy to run into him on the ski trails! His open generous heart will be missed by all of us.

  10. Pete was a link to my parents– my father in particular. My dad was also born in Seattle (about 10 years earlier than Pete) to a Norwegian immigrant father. They moved in similar circles of skiing-climbing enthusiasts, and had some mutual friends from that era. My parents met Pete a few times at Ancient Skiers in Sun Valley, so Pete always inquired about them. I’ll miss seeing him on his bike outside Ideal market and having those little touchstone chats on our Seattle mountaineering roots.
    I also greatly admire Pete’s slice through soils and geomorphology. I keep several editions of his book on my shelf, and cite his 2003 Geomorphology paper on integrating soils and geomorphology in the Front Range in everything I’ve published on the Front Range. There was much to plumb on his knowledge and insight into the local landscape.
    My condolences to Sue, Karl and Robin. Pete was smart and fun and enthusiastic about life.

  11. Pete’s passing brings back wonderful memories of my 1979-80 sabbatical on a Fulbright Research Scholarship Award to study volcanic soils in the western United States with Pete and the Volcanic Hazards team of the USGS led by Rocky Crandell, then based in Denver. Pete proved to be a wonderful host and we will never forget spending Christmas Day with Pete and his family in 1979. In fact going off into the foothills to select a Christmas tree with him and fellow colleagues was a very funny occasion. As everyone says he had a special relationship to his students. What other staff member had a piece of cheese hidden in his office for weeks to the extent that he finally had to search for the source of the rancid odor? Although I’m a long way away in New Zealand I feel close to Colorado right now. Rest in peace Pete. You made a difference to the world. Heartfelt condolences to all the family.

  12. Pete was a great mentor and gracious with his time. He was always happy to join me in the field even though he had retired long ago (I finished in 2016!). He could always quote some thesis over the past 30 years that would solve a question. One of my favorite memories is Pete hopping into a giant house excavation to look at a soil and then looking up at me to ask “do you have a phone? Okay, good. We can call Sue if I can’t get out here.”

  13. Pete’s influence on my career defies adequate words. I first got to know of Pete as. Masters student in Australia when i bought his fist book! I then arrived at CU for my PhD and immediately put Pete on my dissertation committee as I knew my dissertation would be on some aspect of soil geomorphology. His insights into the nuances of the relationships between soil and geomorphology are insurmountable!
    Geomorphology has lost a giant of the field.
    RIP Pete!

  14. Pete’s way of thinking about soils and landforms transformed my own way of looking at the world. To this day, I try to get students to see through his spectacles. But more importantly was how he treated people, with a sense of humor and with respect for their way of looking at the world. Again, I do my best to try to pass on that positive outlook and enthusiastic outlook to students. Biking and mountains — I hope that this passion keeps me going as strong. My wife (Denise) and I have made it to over 40 years and I would love to reach over 60. Alas, I’m addicted to hot temperatures in deserts instead of the snow. So I hope that the snow is not a necessary part of the equation of a very long and happy life!! I promise to keep passing on as much of the humor in fieldwork as possible!

  15. I had a phone call from Bruce Harrison to tell me that Pete has passed away. It is a while since I last exchanged messages with Pete but he was always there in the back of my mind especially as I get older and dwell in the world of memories and the times that I shared with Pete here in New Zealand and the times when I passed through Colorado and spent times with Pete and his students. Everywhere he travelled Pete made friends and influenced people in the world of soils and geomorphology. Such was the power of his personality. The most resent of Pete’s fan club to pass through the South Island of New Zealand with her partner on a bike tour was Janet Slate. I also maintained contact with Scott Burns who kept me up to date with news of Pete. The linkage to Pete the Ped was present here in New Zealand with Pete spending a sabbatical and a send period of study leave and Scott Burns and family a Post-Doc at Lincoln University, and on a latter occasion Bud Burke spent two periods in north-east of the South Island and on the second occasion had a group of his students from Humbolt State with him. Pete’s third edition of Soil Geomorphology was hot off the press and Bud gave me their copy signed for Pete by Bud and the students. So it is with some sadness that the age of Pete is at an end and yet there will be memories and stories that will pass on into the future as part of our shared history. I send my thoughts to Sue, Robin and Karl and hope that the best of Pete stay in your memories supported by the knowledge that Pete was held in a special place amongst his students and friends.
    Philip Tonkin

  16. I was lucky to take Professor Birkeland’s soil course during the Spring 1979 semester at CU, having driven from University at Buffalo as a grad student, tagging along with my Professor Parker Calkin, to spend a semester at the Arctic & Alpine Institute. His lectures and field trips just turned on so many light bulbs in my head!! His love of students, soils, and teaching during that one semester are so vivid to me, especially today as I am reminded how time moves along. The unique and grounded knowledge I gained during his course enabled me to better interpret , explain, and teach about remote sensing images of the Earth for more than four decades. What a gift. What a wonderful memory.

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