Time in Oregon is divided into two zones, with the vast majority in the Pacific Time Zone. Most of sparsely populated Malheur County, including its largest city, Ontario, and its county seat, Vale, are in the Mountain Time Zone due to their proximity to Boise, Idaho. The time zone division occurs at the southwest corner of township 35S, range 37E (approximately 42.597 degrees north latitude), continuing east to the state line, then south along the Oregon-Idaho border to the Nevada state line.[1]