Complex sentence: The Tocobaga were engaged in transporting produce from Apalachee Province to St. Augustine, carrying it in canoes along the coast and up the Suwannee River and, probably, the Santa Fe River, where other people carried it overland the rest of the way to St. Augustine.
Split into simpler sentences: The Tocobaga were engaged in transporting produce from Apalachee Province to St. Augustine, carrying it in canoes along the coast and up the Suwannee River and, probably, the Santa Fe River. Other people carried it overland the rest of the way to St. Augustine.