Question re. veggie products in the USA (update #15)

[Kirsten]

My sister and her husband will come to the US for vacation this fall, they will be in the area around Las Vegas, as far as I know, and rent a camper.

My sister's a veggie like me, so she was wondering if there are vegetarian products such as soy sausages or veggie burgers available in American supermarkets. She's not sure if she can bring her own products with her because there are import restrictions for food when you come to the USA.

So, does anyone know if she can buy these things over there?

Thanks in advance,
Kirsten