It continues to happen every year, NHL teams draft players from high school and the USHL, two leagues that generally act as feeder leagues for the NCAA. The USHL is far more successful at producing NHL talent than high school hockey, which has to be the worst level to evaluate a player. The quality of the competition is so weak compared to Canadian junior that projecting a high school player into an NHLer is incredibly difficult. From 1995 - 2003, only Tom Poti, Paul Martin, and Brian Boyle were drafted from HS and went on to play at least 160 NHL games. That's hardly an impressive list of all-stars.
Of the players drafted from this demographic, 95% go on to attend college and play in the NCAA. Of the players who play in the NCAA, 73% will stay for 4 years. Of the players who stayed 4 years in college, 10% went on to play 100 NHL games. Of the players who left college after fewer than 4 years, 34% went on to play 100 NHL games (suggesting that leaving college early triples your probability of an NHL career). It is difficult to say whether good players leave early because they are destined for a professional career, or does leaving early help improve your chances of a pro career? When I am a General Manager in the NHL, it will be official policy that we do not draft players from American high school teams. The USHL however is a respectable source of talent, if you don't mind waiting 4-5 years before players turn pro.
If you use the metric that 160 GP provides the measure of a successful pick as some academics have, American high school has roughly a 6% success rate. The USHL has an 18% success rate by comparison with players like Ryan Malone, Joe Pavelski, Matt Carle, David Backes, and Tyler Arnason.