Start at Ragged Hills Wayshrine and go to Treva’s Farm, following the road going north. At the farm follow the path going northwest. You can see on your map that this road forms two loops, looking like number 8. The skyshard is in the middle of the left loop, lying on the ground at the base of two rocks and a tree. Be careful, a mammoth is roaming nearby.
Sand Kingdom Moons - Super Mario Odyssey Power Moons