Supposed to be, although there's a tiny population that exhibits the majority of the physical looks of them although it's unclear how much (if any) actual Alvord genetics vs Lahontan genetics are involved.
Yeah they are functionally extinct. I posted a little blurb about them in the thread about summer too, but basically they were in 2 small streams in the alvord desert, those streams got stocked with rainbows and then the alvord cutthroat genetics got hybridized and overrun, then later people found the fish that I caught in a different, previously fishless stream, and were unsure of when they were stocked (if the stocking of the alvord occurred before or after the pure genetics of the original strain were lost). The stream they’re in has lahontans too, that’s where I caught the lahontan in the picture. So they’re a) not native to the stream they were caught in, b) might not be from a pure genetic line, and c) might have hybridized with lahontans as well. In my opinion, there is definitely at least a distinct difference between the alvords and the lahontans in the stream, and the alvords were bigger on average and held the best feeding lies. Here’s a pic of some of the “alvords”
Comparing the larger ones to larger lahontans, the spots look more grouped towards he back and the lateral red stripe is really pronounced along with the rosy cheeks. That could just be a function of their environment and the genetic selection though and not really proof of being alvords. I just kind of got sick of learning about trout and how pretty much all native populations are worse off now so I chose to be selectively optimistic about these ones haha. Worst case scenario, I caught some cool looking trout up to 14 inches in a stream I could jump across!