I wouldn't be too sure the Colombians/South Americans were clean. Just on climbers since I've been watching climbing, there's been Botero in the early 2000s who was linked to Operacion Puerto. There's Soler who has done nothing really since 2007 in the Tour. There's Rujano and Serpa who both ride for Savio's Androni, and even with others, a lot have rode for teams that have had riders convicted of doping.
Henao and Uran are with Sky and are talented climbers