Which U.S. States Are Split by Two Time Zones?

Texas's split is the most geographically logical on the list. El Paso and Hudspeth County are so far west that El Paso is closer to Los Angeles than to Houston — by about 200 miles. The city shares a metro area with Ciudad Juárez, Mexico, which runs Mountain Time. When someone in Dallas calls El Paso at 9 a.m., it's 8 a.m. at the other end of the same state. Mountain Time in El Paso isn't an anomaly; it's the only arrangement that makes practical sense.

Nevada's Mountain/Pacific split exists almost entirely because of one town: West Wendover. The community sits directly on the Nevada-Utah border, and its economy runs on serving Salt Lake City's weekend gambling traffic — Salt Lake is Mountain Time. The DOT placed West Wendover in Mountain Time to align it with its customers. Jackpot, a smaller casino town near the Idaho border, was placed in Mountain for the same reason: it serves Idaho traffic, and Idaho's southern counties run Mountain.

Idaho's Pacific/Mountain divide is one of the sharpest in the country. The northern panhandle — Coeur d'Alene, Sandpoint, the communities that orbit Spokane — runs Pacific. The rest of Idaho runs Mountain. The boundary was drawn because the panhandle's entire commercial gravity points toward Spokane, Washington, not toward Boise. Driving south from Coeur d'Alene into central Idaho crosses a time zone line that has nothing to do with longitude and everything to do with which city anchors the region's economy.

Oregon's split is the least known. Malheur County, in the state's arid southeast corner, uses Mountain Time. The county's towns — Ontario, Nyssa, Vale — sit right on the Idaho border and do most of their trade with Boise, which runs Mountain. It's effectively Boise's time zone applied to an Oregon county — one of the cleaner examples of commerce drawing the clock line.

South Dakota divides cleanly through its center. The Black Hills — Rapid City, Deadwood, Hot Springs — run Mountain; Sioux Falls and Pierre run Central. North Dakota has a smaller version in its far southwestern corner, where three counties along the Montana border follow Mountain. Nebraska and Kansas work the same way: panhandle and far-western county pockets whose grain schedules and trade routes run toward Colorado and Wyoming, not east.

Alaska covers so much longitude — roughly 57 degrees — that it crosses multiple natural time zones. Federal code places the state in Alaska Time for its populated regions, with the far western Aleutian Islands (west of 169°30′ W) in Hawaii-Aleutian Time. In practice, the Hawaii-Aleutian portion of Alaska is nearly uninhabited — it covers remote western Aleutian islands including Attu, the westernmost point of the United States. For almost every Alaskan, there is one clock.

Arizona's situation is structurally different from every other state on this list. The DOT doesn't draw a time zone boundary through Arizona — the whole state falls under Mountain Time. What sets Arizona apart is DST: Arizona doesn't observe it, so the state stays on MST year-round. The Navajo Nation, which covers a large reservation in northeastern Arizona (as well as parts of Utah and New Mexico), observes DST by tribal decision. During summer months, Navajo land runs one hour ahead of the surrounding state. And the Hopi Reservation — which is completely enclosed by Navajo land — does not observe DST, putting it back in sync with the rest of Arizona. Driving across reservations in summer can mean passing through three different effective clock settings without leaving the state.

Whether Arizona counts as a split state depends entirely on what you're measuring. By federal boundary lines: no. By clocks that differ inside state borders: yes, seasonally. The honest answer is 14 states under federal code, 15 if you're counting what a traveler crossing northeastern Arizona's reservation land actually encounters on the clock.