Warner Lakes redband trout are endemic to the Warner Basin of south-central Oregon and northeastern California. A very small portion of this basin occupies the extreme northeastern part of California, with three primary watersheds draining the northern and eastern flanks of the Warner Mountains, flowing north into Oregon. No comprehensive distribution surveys have been performed for the Warner Lakes redband trout within California, so it is currently unknown if they inhabit all three drainages or portions thereof.
here is also speculation that Warner Lakes redband trout occupy several streams draining the eastern flank of the Warner Mountains into Surprise Valley (Alkali Flats). Genetic studies are underway to answer this question. At this time, fish captured in streams within Surprise Valley and the surrounding hills that exhibit the characteristics of Warner Lakes redband trout will qualify, along with the north-draining tributaries that flow into the Warner Basin.