Complex sentence: However, this route led through territory held by Sioux indians who were often at odds with the Ojibwa indians of the upper St. Croix who frequently acted as guides for the European explorers.
Split into simpler sentences: However, this route led through territory held by Sioux indians who were often at odds with the Ojibwa indians of the upper St. Croix. The Ojibwa frequently acted as guides for the European explorers.