Emigration Canyon & Lower Parleys Canyons
By William Case
This Is The Place Heritage Park is situated on the north side of Sunnyside Avenue near the mouth of Emigration Canyon to commemorate pioneer emigration. It is a fitting start to the Emigration and Parleys (named after Mormon pioneer Parley Pratt) Canyons geologic road log. The route climbs up Emigration Canyon Road to Little Mountain Summit, descends to SR-65 and I-80, and ends at the mouth of Parleys Canyon.
The roads pass through sedimentary rocks of Triassic, Jurassic, and Cretaceous ages. Much of the route is in the Jurassic Twin Creek Limestone, which includes oolitic, sandy, silty, fossiliferous, massive, and/or shaley (some intensely shattered) limestone. The formation also consists of small amounts of red siltstone and shale. The red shale at mile 0.9 may be a remnant of an ancient soil or erosion surface.
The next unit encountered in Emigration Canyon is the Jurassic Preuss Sandstone, which consists of chocolate-brown sandstone and fine-grained brown and white conglomerate. In places near Little Mountain Summit, the river-deposited sandstone shows cross-beds and drag-marks made by driftwood or other objects.
The white limestone portion of the Cretaceous Kelvin Formation, which was probably deposited in shallow lakes near a source of sand and fine-grained gravel, locally contains scattered black pebbles.
The Triassic Ankareh Formation can be seen at the mouth of Parleys Canyon where the red and white rock layers are steeply tilted on the southeast flank of the Parleys Canyon syncline. The red rocks on the north side of the canyon mouth contain mud cracks and small ripple marks, which were created by shallow water that gently lapped back and forth across a mud flat that occasionally dried up. The large ripple marks on the white quartz conglomerate indicate energetic currents in stream channels.
The rocks of Emigration and Parleys Canyons are folded into northeast-trending troughs (Emigration and Parleys Canyons synclines) on either side of a folded ridge (Spring Canyon anticline). The rocks were gently to intensely folded and faulted during the Sevier Orogeny 120 to 50 million years ago in this area.
Emigration and Parleys Canyons have provided access to the Salt Lake Valley since pioneer times in the mid 1800s. In 1846, the Donner Party carved their way through Emigration Canyon on their way to California.
To clear the canyon’s trees and brush for the wagon passage required so much work that by the time the party reached the narrow, highly thicketed gorge at the canyon mouth they were so frustrated that, in desperation, they pulled the wagons over a ridge to bypass the gorge. The Donner Hill monument (mile 0.7) commemorates this effort.
In 1847, Mormon pioneers followed the Donner Party trail but cleared a way through the thicket instead of going over Donner Hill. Trail markers show the “Pioneer Trail” from Little Dell Reservoir, across Little Mountain Summit and into Emigration Canyon.
Wagons were unable to pass through Parleys Canyon until 1850 when Parley Pratt cleared the last three miles through a deep, winding gorge with a rough bottom. Stagecoaches began to use the canyon in 1858 and the Pony Express in 1860, but the services were dropped by 1869 when the Transcontinental Railroad was completed.