Shall I visit Canada with out USA visa stamping?

[Suma2288]

I am working in USA on H1B visa. My visa stamping in passport was expired in sep 99. Due to various reasons, I have not got stamped with my new H1B. I have only valid I-94.

Now I want to visit Canada and want to be there for 2+ months. Can I get Canada visitor visa with USA visa stamping?

ARE US authorities allow me to comeback to USA only on I-94?