KMZs and other files showing the distribution of Redband Trout are available from the download system.
Redband is the common name for native-strain rainbow trout which live east of the coastal region. They are classified as subspecies of rainbow trout, with multiple sub-variants which are not necessarily consistently described. For simplicity, we can classify Redbands as belonging either to the Columbia Basin or Great Basin subspecies, lumping together the many sub-variants into two sub-classes.
The Columbia Basin redband describes rainbow trout inhabiting rivers east of the Cascade Mountains, in a broad but poorly documented swathe from central Washington, northern and eastern Oregon, much of Idaho, and brushing western Montana and north-eastern Nevada. These are generally stream-resident populations, though sea-run redband populations also occur. This is roughly the same distribution of Steelhead, which is the sea-run form of the coastal rainbow trout. In some streams redband and coastal steelhead live together (“sympatric”), in others, because of barriers to the steelhead run, redband live isolated (“allotropic”). Steelhead, redband trout, and stocked rainbow trout can interbreed, and do, though because of behavior differences, the sympatric steelhead and redband populations are surprisingly distinct.
The Great Basin redbands include the McCloud River redband, the Goose Lake redband, and the Warner Valley redband, all in California, as well as populations in south-central Oregon and NW Nevada.
Redband trout are considered to be a more primitive form of rainbow trout than the coastal populations which have been stocked virtually everywhere trout live. True redbands are considered the evolutionary link between an ancestral “cutthroat-like” species and the coastal rainbow trout. In general, redband trout possess characteristics that are closer to cutthroat trout than to rainbow trout, such as presence of a faint orange cutthroat mark under the jaw; presence of vestigial basibranchialteeth* in some fish; pronounced white or yellow tips on dorsal, anal, and pelvic fins; higher scale counts; fewer pyloric caecae; and elliptical rather than rounded parr marks (adapted from Ronald Rhew, Redband Trout and the Endangered Species Act).
As an angler, when you catch a rainbow-like fish with these characteristics in the appropropriate geographic range, you may be hard pressed to tell the difference between a “pure strain” redband, a cutt-bow hybrid, or a rainbow/redband hybrid. If the fish is unusual and pretty, maybe that’s enough. But this potential for confusion is one of the reasons I suspect redbands have lagged other native western species in attention and study. Redbands are not considered threatened or endangered (though pure strain populations are increasingly rare); they have one of the broadest distributions of any western native trout.
There is no range-wide assessment of Redbands as there are for many other natives. We’ve had to cobble together information from a variety of sources to paint a reasonable picture of its current distribution. All of these datasets are available on the download system.
- Rust red areas in the image show the historic range of redband trout, based on image overlays captured from an online web mapper put out by the Wild Earth Guardians (http://wildearthguardians.org). I suspect the underlying data comes from some work by the eminent fish biologist Robert J. Benkhe, who described the historic range of the redband in a 1992 paper, but he’s not credited on the site.
- Purple, teal, and black areas in the image show current “predicted’ ranges of redband trout at the sub-watershed level. Teal areas are sympatric with steelhead. Purple are allopatric. Black areas are predicted “strong” populations. These are photo overlays of small-scale maps reproduced in a paper by Thurow, et al. Distribution and Status of Redband Trout in the Interior Columbia River Basin and Portions of the Klamath River and Great Basins, by Oregon Chapter, American Fisheries Society, 2007.
Unfortunately, the projection of these maps was not very compatible with Google Earth’s, so it’s impossible to get perfect registration. We’ve aligned the images in central Idaho. If your interest is anywhere else, you can almost certainly get beter registration by adjusting the alignment to minimize local errors. Just right click on overlay in the sidebar, and select “Properties” (Windows) or “Get Info” (Mac). Green lines will then appear in the center of image: if you click on them you’ll then be able to shift the overlay. Make sure you’re zoomed out enough to see the center. You probably don’t want to rescale the image, so make sure you use only the central crossed lines.
- The red streams in Central Oregon and Montana come from these states’ respective Fish and Wildlife departments, from a dataset published by StreamNet. Unfortunately, neither Washington nor Idaho currently have similar redband data.
- The red streams in northern Nevada some from maps published in the form of a PowerPoint presentation by Nevada Department of Wildlife to the Resident Redband Trout Workshop, May 5-6, 2009. We studied the maps, and marked the stream segments where Redband occur.
- The squiggles in northern California come from the redband layers of the Moyle dataset. These are available individually from the “redband” download page, or the complete CA Natives set (which adds information about Goldens, Cutts, and others) is available from the California download page in the “Streams” category of the download system.
*Teeth on the median ventral plate (base of tongue) overlying basibranchial bones between the gill arches. Basibranchial teeth are often considered a distinguishing feature of cutthroat trout and used to separate them from rainbow and redband trout or steelhead. However, not all populations/forms of cutthroat trout have these teeth, and some rainbow/redband populations do have them. Basibranchial teeth in juvenile fish of all three species may be undetectable. (NOAA)