Three Island Crossing on the Snake River


Three Island Crossing from a 19th century painting

As I mentioned in my August 15 post last year, by mid-August the wagon trains to Oregon were following the Snake River. At the time, the Snake was called the “Lewis Fork” of the Columbia River (named after Meriwether Lewis). The Oregon Trail followed this river for 300 miles from Fort Hall through what is now southern Idaho until it reached Farewell Bend, where our pioneer forebearers headed into the Blue Mountains up to Whitman Mission.

As they followed the Snake, the travelers had plenty of good water nearby. But it was hard to get to the water, because they rode along high plateaus that were often 200 feet above the river, and blocked by huge falls. High cliffs of volcanic rock trapped the Snake into roiling cascades, and its banks were difficult to navigate on foot or horseback. Taking the wagons down to the river would have been impossible.

But beyond getting water, the emigrants faced a lack of grass for their animals and game to hunt for their own food. The land along the Snake held plenty of sand and sagebrush, but that didn’t feed either humans or teams.

And the country was hot and dry in August – highs were 90 degrees or above, no trees for shade, and practically no rain throughout the summer. (Idahoans today will attest to the harsh summers in the region.)

The wagon trains traveled along the southern bank of the Snake until they reached the ford at Three Island Crossing, where they crossed to the river’s northern bank. The ford was near what is now Glenn’s Ferry, Idaho. (Gus Glenn did not open his ferry until 1869; the town took its name from him.) The ford was called Three Island Crossing, because the emigrants took their wagons from island to island across the river.

Three Island Crossing is about 27 miles below Salmon Falls, the last of the great falls on the Snake. The river at the ford was wide and the current swift, but it was shallow enough in the low water of August that they did not have to swim the teams nor float the wagons.

In 1836, Narcissa Whitman described crossing the Snake as follows:

 . . . The river is divided by two islands into three branches, and is fordable. The packs are placed upon the tops of the highest horses and in this way we crossed without wetting. . . . The last branch we rode as much as half a mile in crossing and against the current too, which made it hard for the horses, the water being up to their sides. Husband had considerable difficulty in crossing the cart. Both cart and mules were turned upside down in the river and entangled in the harness. The mules would have been drowned but for a desperate struggle to get them ashore. Then after putting two men swimming behind to steady it, they succeeded in getting it across. “ Mrs. Marcus Whitman, August 13, 1836

A few years later, William T. Newby, who traveled in the Great Migration of 1843, wrote:

We crawsed Snake Rive[r].First we drove over a part of the river one hundred yards wide on to a island, the[n] over a northern branch 75 yards wide on a second island; then we tide a string of waggons together by a chane in the ring of the lead cattles yoak & made fast to the waggon of all a horse & before & him led. We carried as many a[s] fifteen waggons at one time. We had to go up stream. The water was ten inches up the waggeo[n] beds in the deepe plaices. It was 900 hundred yards acraws.” William T. Newby, September 11, 1843, in “William T. Newby’s Diary of the Emigration of 1843,” edited by Harry N.W. Winton, Oregon Historical Quarterly (September 1939), 4:219-42.

If the emigrants waited until the more difficult “two island crossing” a mile upstream, they would have to float the wagons. Unfortunately, many wagon companies didn’t have good instructions, and waited until the harder passage.

Main_Oregon_Trail_ID 3 island crossing cropped

Three Island Crossing today

As described in the quotes above, crossing the river required substantial preparation. Men stationed themselves on both banks, and pulled the wagons across with ropes, lashing several wagons together at a time. Sometimes, they roped three wagons abreast, to present a huge mass to counter the swift current.

The men moved each group of wagons from the near bank to the first island, and then to the next island, and the third, and on to the far bank – about a 900 yard journey from bank to bank. (This gives a new perspective to the term “island hopping.”)

Men rode horseback in the river alongside the wagons, to catch any items that drifted away. Because the wagon beds could be underwater by several inches, each wagon had to be packed carefully before it set out, and then unpacked and checked for dampness after making the ford. Sometimes, the emigrants took the time to raise the wagon beds on blocks to minimize the losses to the river.

It could take three days to get an entire wagon company across all three islands. Even though the river was not extremely deep, the wagons could capsize, and livestock could drown. In 1845, men died at the crossing when a team of mules got tangled.

Nevertheless, the emigrants couldn’t tarry long. Their guides told them if they weren’t finished with the Snake crossing by August 21, they might not make it through the Cascades before winter snowfalls began. So once they forded the Snake, they hurried on to Fort Boise. They still had ford the Boise River, and then the Snake again, before they reached the fort.

Residents of Glenn’s Ferry reenact history at Three Island Crossing every August, so people of today can see how grueling it was. For more on the crossing, see the Pathways of Pioneers website, the National Park Service website, or the Oregon Trail website.

When have you had to prepare for a grueling journey?

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  1. Just last Wednesday, Lowell and I did a day’s jet boat trip through Devil’s Canyon on the Snake River (north of the Boise area) and heard many hair-raising accounts of early trips.

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