I bought a small box of Purex powdered detergent at Dollar Tree and packed it in my checked bag. I did put it in a ziploc, just in case. I brought the whole box because I was paranoid that they would find baggies of unidentified white powder in my bag and freak out!
I also threw some dryer sheets in with my clothes, but I ended up buying a box of two for a dollar in the laundry room. It was two dollars per load (at Wilderness Lodge) for the washers and the same for the dryers, although we did have to run the dryer twice to get the clothes dry. It was a lifesaver to do laundry while we were there, as we didn't have to pack nearly as many clothes. I just used our large suitcase for the dirty laundry and then put the clean laundry back into the ziploc bags I had packed them in originally.
