As a Brit who's recently had some, err..., entertainment with US immigration and US customs over exactly those issues at the Canadian border, I wholeheartedly agree with FFF.
The various arms of US authority at the borders do not seem to have a very clear grasp of what is and isn't currently legal, nor do they appear to talk to each other very often, if at all. Hence do please err on the side of caution and get yourself a visa for your trip, even if technically it's not a necessity!
Of course, when it's all sorted and you get to fly down from Vancouver to Reno it's all wholly worthwhile - flying in America is a fantastic experience and one I hope soon to repeat!
...As this thread is titled "Canada", however, I'll point out that I've done nearly all my flight training, and all my ratings, there and would recommend it in an instant to anyone!
SSS