Rheinschild enrolled at the University of Michigan in 1904 and played for Fielding H. Yost's  Michigan Wolverines football teams of 1904, 1905, and 1907.
 Rheinschild also threw the shot put for the Michigan Wolverines men's track and field team alongside world record holder Ralph Rose, and played catcher on the Michigan Wolverines baseball team.

When Rheinschild established himself as a starter for Michigan in 1905, the Los Angeles Herald reported on his success as follows:
Walter Reinschild, formerly a star player of the Los Angeles high school football team, is making good with the University of Michigan squad this year.
 He played right tackle in the game against Vanderbilt university last Saturday and made consistent gains when given the ball.
 According to reports of the game Reinschild hit the opposing line low and hard and his work was a factor in winning a decisive victory for 'Hurry Up' Yost's team.
 It looks as though Reinschild would be a fixture on the team.

In late 1905 and early 1906, charges of professionalism were leveled at the major college football programs, including Michigan, leading to calls for reform or even elimination of the sport from college campuses.
 In response to the controversy, the faculty at Michigan ruled Rheinschild and two other football players, Germany Schulz and Henry Schulte, academically ineligible.
 As a result, Rheinschild missed the 1906 season.
 Rheinschild's hometown newspaper, the Los Angeles Times described the action as follows: "In 1906 a wave of athletic purity swept over the country and the faculty refused to allow Rheinschild to play, for appearance sake. ... '
Rhiney' assisted Yost with the coaching and did some classroom work for a change."

Rheinschild returned to the football team in 1907.
 Playing at tackle and occasionally at fullback, he scored three touchdowns in Michigan's victory over Michigan Agricultural College (now known as Michigan State University) in October 1907.
 He also scored touchdowns against Wabash College and Ohio State in 1907.
 At the end of the 1907 season, Rheinschild was one of two Michigan players selected by Fielding H. Yost for the All-American team he selected for the North American Press Syndicate.
 He was also selected as an All-Western tackle by Walter Eckersall, who wrote that Rheinschild "has no equal at tackle."
 Eckersall continued:
Rheinschild of Michigan played close to the top this year, and his work in the Pennsylvania game would have given him even without his work in the other games.
 It was the best of any tackle on the field, and clearly indicated his caliber.
 One of his points is getting down the field under kicks.
 He often beat his ends down, and was sure and deadly in his tackle.
 He was not made use of sufficiently in offense to get his value in that respect.
 He was able to lunge from his position with extreme rapidity, to assist either the offense or defense.
 His play was, if anything less showy than in former years, but fully as effective, and this was clearly demonstrated all year.

Rheinschild graduated from the University of Michigan in 1908 with a law degree.
Rheinschild enrolled at the University of Michigan in 1904 and played for Fielding H. Yost's  Michigan Wolverines football teams of 1904, 1905, and 1907.  Rheinschild also threw the shot put for the Michigan Wolverines men's track and field team alongside world record holder Ralph Rose, and played catcher on the Michigan Wolverines baseball team.
When Rheinschild established himself as a starter for Michigan in 1905, the Los Angeles Herald reported on his success as follows:
Walter Reinschild, formerly a star player of the Los Angeles high school football team, is making good with the University of Michigan squad this year.  He played right tackle in the game against Vanderbilt university last Saturday and made consistent gains when given the ball.  According to reports of the game Reinschild hit the opposing line low and hard and his work was a factor in winning a decisive victory for 'Hurry Up' Yost's team.  It looks as though Reinschild would be a fixture on the team.
In late 1905 and early 1906, charges of professionalism were leveled at the major college football programs, including Michigan, leading to calls for reform or even elimination of the sport from college campuses.  In response to the controversy, the faculty at Michigan ruled Rheinschild and two other football players, Germany Schulz and Henry Schulte, academically ineligible.  As a result, Rheinschild missed the 1906 season.  Rheinschild's hometown newspaper, the Los Angeles Times described the action as follows: "In 1906 a wave of athletic purity swept over the country and the faculty refused to allow Rheinschild to play, for appearance sake. ... 'Rhiney' assisted Yost with the coaching and did some classroom work for a change."
Rheinschild returned to the football team in 1907.  Playing at tackle and occasionally at fullback, he scored three touchdowns in Michigan's victory over Michigan Agricultural College (now known as Michigan State University) in October 1907.  He also scored touchdowns against Wabash College and Ohio State in 1907.  At the end of the 1907 season, Rheinschild was one of two Michigan players selected by Fielding H. Yost for the All-American team he selected for the North American Press Syndicate.  He was also selected as an All-Western tackle by Walter Eckersall, who wrote that Rheinschild "has no equal at tackle."  Eckersall continued:
Rheinschild of Michigan played close to the top this year, and his work in the Pennsylvania game would have given him even without his work in the other games.  It was the best of any tackle on the field, and clearly indicated his caliber.  One of his points is getting down the field under kicks.  He often beat his ends down, and was sure and deadly in his tackle.  He was not made use of sufficiently in offense to get his value in that respect.  He was able to lunge from his position with extreme rapidity, to assist either the offense or defense.  His play was, if anything less showy than in former years, but fully as effective, and this was clearly demonstrated all year.
Rheinschild graduated from the University of Michigan in 1908 with a law degree.
Walter Rheinschild