Best Observation Points By Automobile
- Drive south on eastbound US 12 from Pasco, WA. After crossing the Snake River, notice the gaping void across the Horse Heaven Hills to the south. That is Wallula Gap. Watch as it grows larger and seems to open up and then close as you approach from the north. Approximately 11 miles after crossing the Snake River, there is a roadside pullout for the Fort Walla Walla historical marker, located at N 46.084424°; W 118.909523°. Another good observation point (perhaps the better one) is across from the Wallula, WA post office located at N 46.082360°; W 118.907972°. These observation points provide a view down into the throat of Wallula Gap, the sole outlet for all the floodwaters out of the Pasco Basin. During the largest floods, the water rose almost another 100 feet higher than the tallest bluff on the right (west) side of the gap.
- Continue south on eastbound US 12, at Wallula Junction, turn right (westward) on to SR 730. This highway will take you into Wallula Gap. Approximately two miles after exiting on to SR 730 there will be a roadside pullout on the left (east) side of the road for the Two Sisters historical marker located at N 46.043838°; W 118.940074° (Figure 1). This is the trailhead for a short 0.2-mile, round-trip hike.
Two-Sisters Trail: A short trail ascends to the base of a pair of basalt pillars, created by extreme erosion of fractured and weakened basalt by the powerful Ice Age floods. Great views are available both up and down the Columbia River from the saddle between the two pillars.
These basalt pillars (also known as “Twin Sisters”) inspired the mythology of the Wallula Gap, where, according to Cayuse Indian legend, Coyote, a spiritual hero of many Indian legends, fell in love with three sisters who were building a salmon trap on the river near here. Each night Coyote would destroy their trap, and each day the girls would rebuild it. One morning Coyote saw the girls crying and found out that they were starving because they had not been able to catch any fish in their trap. Coyote promised them a working fish trap if they would become his wives. They agreed, and Coyote kept his promise; however, over the years he became jealous of them. He changed two of the wives into these basalt pillars and turned the third into a cave downstream. He became a rock nearby so he could watch over them forever.
Trailhead Location: N 46.043838°; W 118.940074° (Figure 1).
Warnings: Stay off private land to the north and east. Parking area is in a pullout along a blind curve in the highway. Use caution when entering and leaving the pullout.
Trail Length / Difficulty: 0.2 mile / Moderate (short but steep trail)
Trail Description: Climb the ladder over the barbed-wire fence and ascend the short trail that leads up the south side of the Two Sisters. The trail climbs 200 vertical feet over a distance of 0.1 mile to the saddle between the two basalt pillars composed of the Frenchman Springs Member of the Saddle Mountains Basalt Formation. Hikers are rewarded with a spectacular view down the throat of Wallula Gap from this vantage point.
Material taken in large part from On the Trail of the Ice Age Floods: A geological field guide to the Mid-Columbia, by Bruce Bjornstad, 2006, Keokee Books, Sandpoint, Idaho.