Kelly Ward was certainly the more accomplished NCAA wrestler, but Chiapparelli's freestyle credentials, in my opinion, make this a worthy debate.
Ward does seem to be a underappreciated all the same. After losing to Lee Kemp in the NCAA finals in 1977, he began to close the gap his junior year (Kemp's senior year). In the Iowa State-Wisconsin dual, Ward became Kemp's only non-win on his record after his true freshman year as they tied 5-5 in the dual. In a truly great NCAA Final that year, Kemp ran up an 8-0 lead entering the 3rd and Ward stormed back to lose 10-8. Highlights from that match can be viewed below. Ward of course would win next year's title after Kemp graduated.
That said, Chiapparelli's overall wrestling career is really incomplete without considering his freestyle accolades. Aside from winning every major high school national tournament and winning an NCAA title, he was also a Junior World Silver Medalist and he earned a number of wins against some of our most elite senior level athletes. He beat Mark Schultz in the 1988 US Open and would lose to him 2 matches to 1 in the Olympic Trials Finals (these matches were partially depicted in Foxcatcher). That same year he would defeat future World gold medalist Lukman Jabrailov in the famed USA vs. USSR Fiesta Bowl Dual (the John Smith-led US team won against a stout Soviet squad). The next year as the US World Cup rep he would earn gold over former World Champ Raul Cascaret (Cuba) and former World Bronze Vorobiev (USSR). Chiapparelli never made a World or Olympic team, but was competing in an extremely competitive era and weight against not only Schultz (3x gold), but also Kevin Jackson (3x gold), Melvin Douglas (4x medalist, 1x gold), and Royce Alger (1x silver). After retiring for four years (which he spent modelling in Paris of all things according to an interview in the Spoken spokesman) he even came back to the sport to place 4th in the 1996 US Open.
Perhaps more than anything, though, Chiapparelli's wrestling style was innovative and far ahead of it's time-- pure funk long before it became a mainstream part of the sport-- and this made his every match 'must see' for wrestling fans at the time. And he was deadly too, owning pins over the likes of Kevin Jackson and Melvin Douglas, and I'm sure many other top tier competitors. Finally, one could also consider his contributions to bridging the worlds of wrestling and MMA as he formed the RAW team that helped usher the likes of Randy Couture, Dan Henderson, Frank Trigg, and other World Team-calibre wrestlers into MMA.
It all comes to criteria, but while Ward is an underappreciated collegiate great, largely due to his overlap with the near unmatched overall greatness of Lee Kemp (who would be on my USA Rushmore) and his lack of a post-collegiate freestyle career, Chiapparelli's freestyle accomplishments and wins, his innovative and dangerous style, and his pioneering work with wrestlers in MMA make him a worthy potential inclusion on a Maryland Rushmore, in my opinion at least.
Kyle Snyder (3x World/Olympic champ, 3x NCAA champ, 1x World silver, Jr World champ)
Helen Maroulis (3x World/Olympic champ, 5x World medalist)
Lloyd "Butch" Keaser (World champ, Olympic silver, 2x NCAA AA)
Kelly Ward (NCAA champ, 3x NCAA finalist)
Others: Rico Chiapparelli (NCAA champ, 3x NCAA AA, Sr US Open champ), Pat Downey (WTT / Final X champ, NCAA AA, Jr World silver), Bill Simpson (NCAA champ), Mack Lewnes (3x NCAA AA (2nd, 4th, 4th))
Toss-up between Ward and Chiapparelli for the final spot.