Car trip to Canada / Niagara Falls. License/birth cert? Passport card? Passport?

I've been 3 times myself, she's never been and I'm looking forward to seeing it with her.

First time was around 1986 or 87, stationed in upstate New York at a nuclear power prototype for training. Me and some friends were bored and did an overnight kinda spur of the moment over a long weekend.

Second time I went back on my own, like January and it was almost frozen over. I went mostly for photos, that was a cold weekend. Driving down the street that runs along the edge and mist blew past my car, the windshield immediately frosted over and couldn't see E36 M3. Stopped to scrape it and realized it was a good spot to set up the tripod (night).

Third was with the ex wife around 2005 in July. Had a good time, bought a couple Cuban cigars for friends and her dad. Coming back I remember the border guard asking if we were bringing anything back to the US. Said a couple souvenirs and a E36 M3load of photos. He just smiled and waved us in.

The two times in the Navy I just needed my ID and probably driver license. Third time I had to get a real copy of my birth certificate, with stamp.

SV reX said:

If you dress in camo and consider a nighttime crossing, there are thousands of miles of entry points that do not require a passport. 

It's 20 years ago now, but the strangest border crossing to Canada for me was snowmobiles across the ice.  Got to the Canadian shore, and there was a phone booth where you called the authorities and gave them identification and vehicle info and were free to go.  We had a handful of people and just handed the phone to the next guy.   Strangely, I don't remember anything about the return.

edit:  sorry, not relevant to the actual question at hand.  I just like the story.