Complex sentence: With several boats from his ship, Broughton and his party navigated upstream as far as the Columbia River Gorge and on 30 October, he reached his farthest point, landing in eastern Multnomah County east of Portland and northwest of Mount Hood.
Split into simpler sentences: With several boats from his ship, Broughton and his party navigated upstream as far as the Columbia River Gorge. On 30 October, he reached his farthest point up the Columbia, landing in eastern Multnomah County east of Portland and northwest of Mount Hood.