throughout the United States with great success. It is costly, but 

 if reintroduction of undesirable fishes can be prevented, the long- 

 term benefits far outweigh the costs. 



Most rehabilitation work has been done on lakes where there 

 is no possibility of undesirable fishes moving up or down the drainage 

 into the lakes and reinfecting them. Recent experiments have shown 

 that streams may also be rehabilitated, providing natural or artificial 

 barriers are present or constructed to prevent fishes from moving 

 into the rehabilitated area. 



Because rehabilitation of waters can be justified in Montana 

 only where there is reasonable assurance that reintroduction of rough 

 fishes will not be made, waters will be rehabilitated only in those 

 parts of the State where use of small fish for bait (minnow fishing) 

 has been prohibited. 



Stream Habitat 



Until the last decade or so, and even at the present time to some 

 extent, there was the popular belief that fish needed no more than 



m&s.' 



Sucker and carp predominate in 

 the rough fish washed ashore 

 (above) alter poisoning. When this 

 lake becomes non-toxic to lish, it 

 will be stocked with desired game 

 ash. 



(Insert at lelt) — Stunted perch 

 and sunfish removed by poisoning 

 from once-good Montana trout lake. 



— 61 



