Maryland Fish Facts


Rainbow Trout
Rainbow Trout

Rainbow Trout
Oncorhynchus mykiss

Key Distinguishing Markings:
  • Rainbow coloration varies widely. The same batch of rainbows grown at two different hatcheries can have noticeably different color intensities and patterns.
  • For the most part, Maryland rainbows have a greenish silver back and a silver sides with a faint red band that travel the length of the lateral line.
  • They are heavily spotted along the sides and top to include the dorsal and tail fins.​
View the Rainbow Trout Gallery

Rainbow Trout 

  • Rainbow trout were transplanted to Maryland from the West Coast of United States.
  • They are native to the Pacific slope from the mountains in northern Mexico through the western United States around Alaska and the Bering Sea to the northern regions of Asia.
  • They have been introduced into every state in the Union as well as introduced worldwide.​

  • The average size range of rainbow trout is 10-13 inches, with some individuals reach 20+ inches​.

  • Rainbow trout are stocked in well over 100 streams and lakes across the state. Trout stocking locations and Current stocking information.
  • A naturally reproducing population is also found in Garrett County's North Branch Potomac River downstream of the Jennings Randolph Lake Dam.​
  • In their natural range, rainbow trout are spring spawners and rely heavily on meltwater from high mountain snow pack to trigger spawning.
  • In Maryland, far removed from their natural habitats, rainbows may spawn sporadically and intermittently at anytime between late summer to early spring.
  • Naturally reproducing populations of rainbow trout are found in only three small streams in Maryland.​

Fishing Tips:

Fun Fact:
  • Rainbow trout take well to life in a hatchery as they are fairly disease resistant and easy to rear.
  • Rainbow trout are the predominant trout grown at Maryland trout hatcheries and they form the basis of our successful put and take trout fishing program.
  • Over 500,000 adult rainbow trout are reared annually at State trout hatcheries  and rearing stations.
  • Rainbow trout are stocked in well over 100 streams and lakes across the state.​

Family: Salmonidae (Salmonids)
Order: Salmoniformes (salmons)
Class: Actinopterygii (ray-finned fishes)

​For more information on rainbow trout and their management, please contact John Mullican - ​(301) 791-4736.

​Illustration courtesy of Duane Raver, USFWS​​