In the Tending style, the flock is managed as it feeds. Traditionally, German farmers did not own the property they grazed their sheep on. In the U.S., it can be difficult to find instruction in the Tending style if you are not in New England, California or Washington state. The working style of a dog gathering it's flock is what I will refer to as Herding. Stock dogs are utilized to move the stock, not to feed them.
American farmers own the land their flock grazes on.
In the U.S. there are practitioners of this style of flock management everywhere, but they are rarely GSD owners. The most common Herding dog is the Border Collie. Color, coat, ear carriage mean little. It is the absence of the 'tool mentality' that defines most GSD herding enthusiasts. Most are involved in herding as a hobby.