Complex sentence: Like many Northwest Coast natives, the Suquamish relied on fishing from local rivers and Puget Sound for food and built plank longhouses to protect themselves from the wet winters west of the Cascade Mountains.
Split into simpler sentences: Like many Northwest Coast natives, the Suquamish relied on fishing from local rivers and Puget Sound for food. They built plank longhouses to protect themselves from the wet winters west of the Cascade Mountains.