Lauren Nicholson (née Kieffer) began riding at the age of six and competed in her first horse trials at the age of 12. As a high school graduation present, Nicholson participated in a week-long eventing summer camp with Olympians David and Karen O’Connor, which led to a six-year working student position and continues to be based with them today. Her talent and work ethic helped her reach the top levels of the sport and represent her country in international championships.

Nicholson was a member of the U.S. Eventing Team at the 2016 Olympic Games, the 2018 FEI World Equestrian Games, 2015 team gold at the Pan American Games in Toronto, and team silver at 2022 World Equestrian Games in Pratoni

She made her debut at the CCI5*-L level in 2010, when she and Snooze Alarm completed the Rolex Kentucky Three-Day Event. Since then, she has had numerous top finishes at the level, including finishing in second place overall and as the highest-placed U.S. athlete at the Kentucky Three-Day Event in 2014 and 2016, where she won the title of USEF CCI5*-L Eventing National Champion. She is also the first American to have top 10 finishes at every 5* in the Northern Hemisphere - Kentucky, Maryland, Badminton, Burghley, Luhmuhlen, and Pau.