Are these shoes good for crossing rivers?

Well, they are not waterproof, so your feet will get wet. They do dry fairly quickly, however, because they are mesh. I would definitely look at any of Chaco's sandals with the Diamond Stealth outsole; it is super sticky and great for river running. Something like this is what you're looking for:

http://www.backcountry.com/store/CHA0035/Chaco-Z-2-Diamond-Stealth-Sandal-Mens.html
View Details: Chaco Redrock Mesh Hiking Shoe - Men's >