Complex sentence: Cody joined the Bonneville Power Administration as a freelance writer for a time, it was during an assignment for the BPA that he was inspired to canoe the Columbia River from its source to its mouth.
Split into simpler sentences: Cody joined the Bonneville Power Administration (BPA) as a freelance writer for a time. It was during an assignment for the BPA that he was inspired to canoe the Columbia River from its source to its mouth.