This Olympic track and field athlete, a multiple Gold Medal Winner, set a record so high that, 36 years later, the effort would have still been good enough to finish 2nd in the Olympics. Who was he, and what was the event?

Bob Beamon --- long jump

I was thinking that someone would say Beamon. Beamon set his record in the Mexico City Olumpics in 1968. While I am confident that his distance will still be a placeholder after 36 years, it has only been 35 years since he set it.
OK, folks, who was it? There are a few clues in the original question:
multiple Gold Medal Winner
he

And now you know that it had to be earlier than 1968 when he set the Olympic record.

More help. He was only in the Olympics once.

Bueller? Bueller? Anyone?

Could it be Ben Eastman in the 1932 Olympics?

Nope.

I am guessing Jim Thorpe, who won 2 medals in 1912, and his mark of 6,765 in the Decathlon would certainly have gotten 2nd in 1948 over Ignace Heinrich's 6,740.

Finally! Good job! Thorpe was an incredible athlete. What many who do know about him still forget is that in that 1912 Olympics, he won not only the Decathalon, but also the Pentathalon. In the 5 event Pentathalon, Thorpe won every pentathalon event except the javelin.

The 1912 Olympic decathlon has become legend because of the presence of Jim Thorpe. He had a almost unbelievable 1912 spring track season, winning as many as six events per meet. Thorpe made the U.S. Olympic team in four events: decathlon, pentathlon, high jump, and long jump. Tsar Nikolas II of Russia donated a Viking ship as a prize for the decathlon champion. Thorpe won the decathlon by almost 700 points over his closet opponent, Hugo Wieslander of Sweden. Because of the unexpected large number of entries, the decathlon was held over 3 days instead of the planned 2 days. The first day they held the 100m run, long jump, and shot put. The second day consisted of the high jump, 400m run, discus, and 110m hurdles. The third and final day consisted of the pole vault, javelin, and 1500 m run. Thorpe’s 8412 points converts to 6564 points on the current tables, still a very respectable score three quarters of a century later. His score was not beaten for 15 years.

Thorpe is credited with one of not only sport's but history's best quotes after winning the Decathalon. "You, sir, are the greatest athlete in the world,” Sweden's King Gustav V said to Thorpe after giving him his 1912 Olympic gold medals. “I would consider it an honor to shake your hand." Thorpe replied, “Thanks King.”

In those Olympics, Thorpe also competed in the high jump, getting fourth, and the long jump, finishing seventh.

To get an idea of just how good at sports Thorpe was, consider the following:

He won Olympic gold medals in the pentathlon and decathlon, starred in college and professional football, played Major League Baseball and also had a career in basketball. He is in the College Football Hall of Fame and the Pro Football Hall of Fame. In 1920, he was the president of the organiation that evolved a few years later into the NFL. He played in the pro football in 1915-1926, and again in 1928. He is on the NFL's 1920s All-Decade Team.

While his baseball career was not outstanding, it was certainly nothing to be ashamed of. He signed with the New York Giants in 1913 and played sporadically there as an outfielder for three seasons. After missing the 1916 season completely, he came back to play again for the Giants in 1917, but was sold to the Cincinnati Reds early in the season. Late in the season, he was sold back to the Giants. Again, he played sporadically for the Giants in 1918 and was traded to the Boston Braves on May 21, 1919. In his lackluster career, he amassed 91 runs scored, 82 runs batted in and a .252 batting average over 289 games. He continued to play baseball with teams in minor leagues until 1922. (Note that he played both pro football and Major League Baseball at the same time. Thorpe is also credited as being the first man to both hit a home run in the Majors and score a touchdown in the Pros in the same week.)

Recently, evidence has come to light that he began a career in basketball. "Jim Thorpe and His World-Famous Indians" barnstormed for two years (1927-1928) in parts of New York, Pennsylvania, and Marion, Ohio. This period of his life is not well-documented, and until 2005 even Thorpe's biographers were unaware of Thorpe's basketball career. Thorpe is the only American athlete to excel at the amateur level and professional level in three different sports – track and field, football and baseball.

Oh, yeah, I almost forgot. Thorpe also won a national ballroom dance contest.

Now what was that talk about an NBA basketball player who played minor league baseball being the greatest athlete ever?