The mom probably came and got the baby when it moved....they usually don't go too far away from the fawns. If her mother isn't around anymore you'd hear the fawn.
I'm a wildlife rehabilitator and I care for orphans and/or injured animals...then return them to the wild if they don't have injures that would handicap them.
If you find any baby the best thing would to leave it alone....if it's a baby bird you can place it back in the nest or up in a tree near by. The only bird that can smell is a vulture so don't worry about the old wives tale about the bird killing the baby because of your scent
Give a call to your state's wildlife and fisheries to get a list of state lisc wildlife rehabbers for next time