Exercise 'Skyshield' involved penetration of NORAD air space in 1961. This included Vulcans which landed at Loring, Stephenville and Plattsburgh (I think - 15 years before my time on Vulcans!).
'Western Rangers' were merely routine trips to Goose, then Offutt and included low level simulated bombing exercises. Each crew probably flew one Western Ranger per year (unless the Boss stole the trip - as was sometimes the case) and they were eagerly anticipated!
A small number of Vulcans were lost in the US over the years, but not during Exercise 'Skyshield'.