Kikkan Randall, who this year teamed with Jessie Diggins to win the United States' first-ever cross-country skiing Olympic gold medal, announced on Wednesday she is battling breast cancer.
Randall, a five-time Olympian and mother of a two-year-old son, wrote about the diagnosis on her Facebook page.
"The colour pink has taken on a new chapter in my life as I was recently diagnosed with breast cancer," wrote Randall, known for her pink-dyed hair.
"Although we caught it early and the prognosis is good, my life will change quite a bit in the coming months."
The 35-year-old had returned to Anchorage, Alaska, for treatment and had undergone her first round of chemotherapy on Monday.
"I am going to bring as much tenacity, strength, and energy toward this challenge as I have throughout my entire career," she vowed.
Randall and Jessica Diggins pulled of a shock win in the women's team sprint freestyle event at the Pyeongchang Games in February, becoming the first Americans to win an Olympic cross-country skiing event.