I live in Colorado and the article is a little misleading to say the least. The fish were not illegally stocked, they were stocked by the dnr in reservoirs upstream and they escaped into the river system. They have been electro-shocking the Yampa river for more than ten years and killing every smallie and pike they catch. They have also been stocking the native species during that time and the populations still are not increasing.
The other thing the article doesn't mention is that smallies and pike are not the only non-native predators in the river, they are just the only species that are being targeted for extermination. Rainbow and brown trout are also non-native species, but they don't kill them because people come to Colorado to specifically fish for trout. Granted, the smallies and pike share more habitat with the native species than the trout do but if they truly wanted to restore the native populations, they would remove all non-native predators.
The whole project is pretty much useless unless they plan on shocking the river until the end of time. There is no way they are going to remove every single smallie and pike from that river system, and as soon as they stop shocking, the populations will go back to their previous levels. In the mean time, all they have accomplished is to ruin what was the premier smallie and pike fishery in the state.