The term 'Sturdy Ponies' can be summarized by the crossword solution 'Cayuses' (7 letters). Cayuses are a type of small horse that originated in the United States. They are known for their strength and endurance, making them ideal for long-distance riding. They are also known for their sure-footedness, which makes them suitable for mountainous terrain. Cayuses are often used as pack animals, and they are popular among ranchers and farmers.