Grew up in the Upper Peninsula of Michigan, where he frequented Wild Pines Golf Course, a nine-hole course in Hermanville, Michigan (near the Wisconsin border) with his grandpa, Steve. The two typically played as many holes as they could until sunset. Eichhorn’s hometown is nearby Carney, Michigan, which had a population of 179 in 2020 census data.

Eichhorn said of honing his game at Wild Pines, “The importance of starting out on a course like that I think helped me understand the importance of a par, a birdie, and a bogey. My grandpa and I used to scramble, so we always practiced shooting as low a score as possible, and making as many birdies as possible. So that’s how I developed the mindset of finding a way to shoot as low a score as possible.”

Prepped at Carney-Nadeau Public School, where, in addition to playing golf and running cross country, he played three seasons of varsity basketball and averaged 23.1 points (with 86 made 3-pointers made, including a single-game record of 12), 5.5 rebounds and 5.2 assists per game as a senior. Eichhorn’s high school graduating class was 17 students (counting him).

First time he got on a plane was his freshman season (October 2017) at Marquette University, when the team traveled to a tournament in El Paso, Texas. Eichhorn recalled, “I was a little nervous at first during the takeoff. But then I focused on the fact we were going to Texas where it’s warm. That calmed me down.” Eichhorn won the event by one stroke with a final-round 65.

Played five seasons at Marquette University (2017-22), where he earned six individual victories, highlighted by medalist honors at the 2018 and 2021 BIG EAST Conference Championship, and broke the school record for career scoring average (71.38). Eichhorn was also a three-time BIG EAST Player of the Year (2018, 2021, 2022) and earned All-America Scholar honors in 2021 and 2022.

At Carney-Nadeau Public School, won individual state title at the Michigan High School Athletic Association Upper Peninsula Championship each of his four seasons on the golf team; he became the first boys golfer in statewide history to win four individual state titles.