Youth football leagues are Colorado’s modern gold mines, where young, impressionable players are discovered. Both public and private schools have long scouted these leagues, but it’s the draw of the private schools that has changed the recruiting game in metro Denver. “There’s been a drastic change in how much the private schools have gone to look for players . . . all the way down to the third-, fourth- and fifth-grade level,” said John Schultz, football coach at Grandview, a public high school in Aurora.