Kolter is a modern American spelling of Colter, an English surname that means "colt herder" or "keeper of colts"; John Colter of the Lewis and Clark expedition was one of the first explorers of what is now Yellowstone. The K-spelling turns a frontier surname into a fresh-sounding first name. Kolter was almost unused in 2000, climbed fast through the 2020s, entered the top 1000 in 2024 and ranks number 600 in 2025.