• adipose fin is present
• adipose fin has one break in its outline
• the length of the base of the dorsal fin is greater than the length of the base of the anal fin
• back of anal fin vertical (no slant, straight up and down)
• parr marks present
• parr marks fairly evenly spaced, although they can vary in length and can be longer than vertical diameter of eye.
• spots on dorsal fin (NOT wavy stripes)
• few or no spots on caudal fin (tail fin)
  
  

Known distribution in Yukon: Alsek River and introduced to streams near Whitehorse, Dawson and Mayo.

Other notable comments and clues:

• The most distinguishing feature of the juvenile rainbow trout is the spotted dorsal fin. There may also be faint pink colouring along the lateral line.
• Keep in mind the distribution of these fish, they only are found in a few areas in the Yukon.
• Rainbow trout are the resident, or non-anadromous species, while steelhead migrate to and from ocean.
• Year of young (0+) rainbow trout in Whitehorse area may be very hard to distinguish from (0+) chinook salmon, use caution when identifying.