I keep them on my phone, but have been stopped 2-3 times when traveling with my wife along the southern border. Arizona, New Mexico, Texas, California, think I have been stopped with her in all of these states, and not once have they asked for any proof of her immigration status. we both show our Nevada state ID/ License, and are sent on our way after maybe a few questions. This was always at a mobile checkpoint they seem to set-up whenever they seem board and want to look like your tax monies are being put to good use. Unless you are rolling in a van or truck loaded with people that look like illegal immigrants, I don't think you will have an issue. I was once stopped by myself years ago, long before I even met my wife and had a real issue at one of these checkpoints coming back from Mexico driving back to Nevada. They really grilled me by myself, and searched my car ( A smart car none the less, like I was hiding a lot in that thing), but still sent me on my way. My wife carries a nice color copy of the front and back of her green card with her, but the original stays in the safe at home( come with us when we travel outside the US only), I'm not going to be out 500 dollars because it gets lost. I told my wife not to worry, if they lock her up I'll get her out... LOL. I know the law states must have it on you at all times, but there are a lot of laws I really kinda don't follow to the letter, and I still get thru life with little hassle.