There are two really good yards at the Erie exit North of Denver off I-25. They are next door to the Erie racetrack, and are on the East side of I-25. You can't miss them! I've had great luck at both yards.
There is another yard near Strasberg on I-70 East of DIA that's good.
Over in Delta, there's Cook's Salvage. He's got lots of Stovebolt stuff, too.