The 120 looks like it would be one of the hottest temps ever recorded outside Death Valley. If you pull the S/W US out, the highest temp in US History was 122 in North Dakota in 1936. But I would hazard a guess that none of the other low 120's feature temps near the extreme for 10+ days straight. That is some extreme weather.
Funny, but I went to look for the Washington forum on here and just realized this site is very East US specific. I never noticed that there is just one sub forum that covers Lewis and Clark Territory plus the S/W.