Looks like this model was originally advertised in the Roll and Go Western Play Set #5934 in 2011, but not verified if any were released, as the Buckskin Cantering Warmblood was widely available. Set included a Running Calf, Border Collie, water trough, fencing and play mat.
The Giddy Up and Go! set included a grey roan appaloosa on the Appaloosa mold, a bay Arabian and a palomino Prancing Morgan along with a truck and trailer. This set is #701736 and was available in 2016.