Northern Nevada, the overwhelming chances are it was a Great Basin(sub species of the Western Rattler) Mojaves haven’t been reported that far North - yet.
I hunt around Winnemucca on a regular basis. In the event of a bite the plan is to return to Reno ASAP. Even have a strategy to meet the Air Medivac at three places along the route.
If it was my kid I would of demanded ambulance air bridge evac immediately. The hospital is little more than a clinic.
Only thing making me think possible Mojave was the respiratory distress. That is a little far north to be finding Mojave’s.