Complex sentence: On the east, the Okanogan River and the Columbia River bound the range in the United States, while the northeastern boundary of the range departs the Thompson via the Nicoamen River and runs via Lawless Creek, the Tulameen River and Copper Creek to the Similkameen River.
Split into simpler sentences: On the east, the Okanogan River and the Columbia River bound the range. The northeastern boundary of the range departs the Thompson via the Nicoamen River and runs via Lawless Creek, the Tulameen River and Copper Creek to the Similkameen River.