Antelope Island & Bonneville Salt Flats: Bison, Hypersaline Swimming, and Land Speed Records

The 7.2-mile causeway across the Great Salt Lake's southern arm delivers the first view of the island's bison herd as the road climbs onto the island's sagebrush slopes. The herd of 800+ animals — descended from 12 calves introduced in 1893 — grazes on the island's native bunch-grass and sagebrush without fencing, which means bison may be encountered anywhere on the island road or trail network. The annual bison roundup in October trims the herd and is one of the most-attended events in the Utah state parks calendar.

Utah's oldest operating ranch (1848) preserves the complete material culture of a 19th-century Great Basin livestock operation: the stone ranch house, stone corrals, icehouse, spring-fed watering system, and the orchards planted by the Garr family in the 1850s. Park rangers interpret the ranch daily in summer; the setting — a pioneer homestead on an island in a hypersaline lake, with the Wasatch Range rising 11,000 feet across the water — is without parallel in the American West.

Bridger Bay on the island's northwest shore is the primary swimming beach for the Great Salt Lake — and the swimming here is unlike any other lake in North America. The lake's salinity (5–27%) produces buoyancy 10 times greater than freshwater; swimmers float with minimal effort, and the dense water makes it impossible to sink even without swimming motion. The brine shrimp ecosystem gives the water a faint orange tint in late summer; the brine flies at the shore's edge (non-biting) are easily left behind by wading out 30 feet.

The western shore of Antelope Island is quieter than the causeway side, with a shoreline trail along White Rock Bay that offers afternoon views across the lake to the Stansbury Mountains and the Great Basin ranges beyond. The lake in afternoon light — especially in July and August when brine shrimp concentrate and the water takes on pink and orange tints — is one of the most unusual landscape photographs available within an hour of Salt Lake City.

The return drive across the causeway at sunset, with the Wasatch Range reflected in still lake water and the Oquirrh Mountains catching the last light to the west, is the signature end to an Antelope Island day. Stopping on the causeway shoulder at dusk is common practice among Salt Lake photographers; the flat water and mountain reflections require no special technique.

The Bonneville Salt Flats extend 30,000 acres across the floor of the ancient Lake Bonneville basin near Wendover, Utah — the remnant of the great Pleistocene inland sea that once covered 20,000 square miles of the Great Basin to a depth of 1,000 feet. As the lake evaporated over 14,000 years, it left a crust of sodium chloride, potassium, and other minerals up to 5 feet deep on the flattest natural surface in North America. The course has hosted land speed record attempts since 1896; the current wheel-driven speed record of 470 mph was set on the salt. The International Speedway on the flats is marked by a timing tower and a series of black distance markers on an otherwise featureless white plain that extends 12 miles to the Newfoundland Mountains on the Nevada side.

Use the afternoon to explore a different side of Bonneville Salt Flats — Speed Week Historic Site — there's more to discover beyond the morning highlights.

Wendover Air Force Base (now Wendover Airport) was the training site for the 509th Composite Group — the unit that dropped the atomic bombs on Hiroshima and Nagasaki. The Enola Gay flew its final training flights from Wendover before departing for Tinian Island in the Pacific; the original 1940s base buildings, the bomb loading pit replica, and the base museum interpret this history. The base is on the Utah side of the state line.

The small Bonneville Speedway Museum in Wendover collects land speed record vehicles, timing equipment, and photographs from the century of racing on the salt flats: the rocket-shaped cars, the streamliners, the wheel-driven record holders, and the community of speed record chasers who have made the Bonneville Salt Flats the world's definitive venue for maximum velocity on land.