In the first photo above, you can see the reflection of the camera flash in the eye of seven brook trout. There are two or more other trout that don't show their eyes. Look for the blue light of the reflection in their eyes.
Rainbow trout and cutthroat trout are also comfortable in numbers, in a confined space. When I was a boy, I would snorkle the Jumpingpound Creek and find pods of rainbow trout, holding below large chunks of fallen sandstone, from the cliffs above. The cliffs were now safe to swim below, so it wasn't like I was sticking my neck out to investigate trout habitats!
Any type of shady nook below large rocks or overhead woody cover, will do for any wild trout population. It goes one step further with willow habitat units. The planted willows in our Bow Valley Riparian Recovery and Enhancement Program are planted up on the stream bank and also horizontally into the stream bank, so they will provide fish habitat when they grow large enough. This habitat is not only for trout, but the aquatic invertebrates that dwell in suspended lateral margin habitat do thrive if that habitat is drowned willow limbs and tree trunks.
The aquatic invertebrates don't have to contend with the huge amounts of silt and suspended fines that smoother the stream beds and limit invertebrate population densities. The following video will help give you a better idea of what I mean when I talk about the relationship between willows, leaves and other organic matter that provides microscopic life forms a home and their important role in a healthy trout stream!