In 2012, Swenson along with Mark Richey and Freddie Wilkinson, made the first ascent of Sasser Kangri II. At the time, the peak was the second highest unclimbed mountain in the world. For their climbing, the team was awarded the Piolet d'Or. In 2019, Swenson, along with Graham Zimmerman, Mark Richey, and Chris Wright, climbed Link Sar, for its first ascent. Swenson had attempted to climb it twice before, in 2000 and 2017. Along with his climbing career, Swenson had a 35-year career as a water resources consulting engineer.