Not all bull trout have the same life history. There are four strategies:

• Resident bull trout are small and live out their lives in small headwater streams.
  
  
• Fluvial bull trout are migratory; they live as adults in large rivers but spawn in small tributary streams.
  
  
• Adfluvial bull trout are also migratory; they spawn in tributary streams but live as adults in lakes.
  
  
• Anadromous bull trout live on the coast, not in Montana. They rear in tributary streams and migrate to marine (ocean) environments to mature.