A web map showing the complete distribution of Gila Trout is available here.
Gila Trout inhabit a tiny range, mostly within the Gila Mountains of NM, roughly mid-way between Albuquerque and Phoenix. 3 other streams have been established in AZ: two in Coronado National Forest, about 75 miles SW of the Gila Mountains, and one near Prescott.
The core Gila restoration area was severly burned in 2012 by the Whitewater-Baldy fire, the largest wildfire in NM history. Of the 15 dedicated Gila Trout streams existing prior to the fire, 9 were either completely eliminated or required a new population to be stocked. Of the 5 “remnant” populations affected, 2 were among those elimnated (A remnant population is one that had never been stocked, surviving with original strain trout for millennia).
If there’s any good news here, it’s that some streams that had been under threat due to the invasion of exotic species (e.g. brown and rainbow trout) have now been cleared of the exotics as well.
As of 2015, there are only two streams where it is possible to catch wild Gila Trout legally: one in NM, and one in AZ.
The NM stream is a short section of Mogollon Creek, sometimes referred to as East Fork Mogollon Creek. It also appears that some wild fish may survive in the South Fork Mogollon Creek, a tributary which flows into the open section of Mogollon Creek, though this is not explicitly listed on the NMDGF website. A special (free) permit is required. Iron Creek, which formerly provided a second wild population, has reopened to fishing, but is currently being maintained with stocked fish. It still requires the same special permit. In addition, there are several stream segments where stocked populations of Gila Trout are maintained for anglers which do not require any special permit. See NMDGF website for details.
The Arizona stream is Frye Creek which was established a number of years ago with fish transplanted from South Diamond Creek. Fishing is subject to a special season: closed during spring and summer, open during fall and winter.
Mogollon, Iron, and Frye Creeks are indicated in bright green in the image below and on the web map. Note that this situation is subject to change. Please confirm current special regulation requirements before going out.
Source: Gila Trout conservation streams identified in a paper presented by Hicks, et. al. at WildTrout Symposium XI. USGS National Map basemap.