Found three puppies in the mountains in a box?

ok so I live in the Tennessee mountains and I have a small 2 mile trail that I walk every morning. this morning I went walking and about half way in up the trail I found three small puppies with a box they look lab mix two are black and one is a rusty color the black ones are female and the rust one is a boy. they are covered in mud as we have had a lot of rain recently. so I went ahead and just left them there and finished my walk of course they had to be all cute and follow me the whole rest of the walk which was about one mile. but surprisingly when we got back to the box where I found them they stayed there I thought for sure they would follow me home and I kind of wanted them to so I could give them a bath and take them to the vet. so now I am wondering if their mom is out there somewhere. so now I am trying to figure out what I should do. should I go back and take just the pups, or should I go back and wait for the mom and then take the mom and the pups or should I just leave them there and hope for the best. and I live in a rural area so we dont have any animal control or anything like that so their is no one I can call to pick them up.