They do have full length side zips on the outside of both legs, but the pants don't come fully apart to two pieces. You can put them on with boots on by zipping the top zipper down to about half-way, and the bottom zipper up to about half-way, so you have lots of room for your boots to fit through and lots of room at the top of the pant for around your waist. However, let's say you had skis on and you wanted to put the overpants on... That won't work, because the pants don't fully come apart to two separate pieces. I hope that helps.