With few exceptions, every major stream in the state is occupied primarily by brown trout. For anglers, this presents a variety of difficulties related to proficiency and altered angling styles. To the degree that browns gain preponderance in the population, fishing gets a lot tougher. The reason won't surprise many veteran anglers who understand the nature of the two species. Rainbows are more aggressive and easier to catch.
Browns tend to be more reclusive and respond less readily to most conventional angling methods.
The reason is rooted in a primary trait that not only inhibits biomass gain, but makes browns more difficult to catch. Most places, they're already at carrying capacity. In a recent snorkel study of 10 sites in the Coller Wildlife Area on the Rio Grande River near Creede, DOW crews found that 80 percent of the browns resided in close proximity to a boulder 2 feet in diameter or larger. Browns require those underwater condos. Rainbows, on the other hand, thrive in condensed numbers in an open-water environment, a trait that not only makes them more accessible to anglers, but adaptable to hatchery life.