Station Camp Observations

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Continuing west on the morning of November 8, the expedition's canoes generally hugged the northern shore of the Columbia's estuary around Grays Bay. That evening they made camp near present-day Portuguese Point. High winds and waves kept them from traveling on the 9th, but on the 10th they continued about 7 miles generally southwest to a small cove about 1 mile northeast of present-day Point Ellice, Washington. Rain, hard winds and billowing waves pinned them to the narrow beach from November 10 and to the afternoon of November 15, eliciting the name Camp Distress for this stopping place. Lewis and a small scouting party set out from Camp Distress on November 13 to explore the area west to the ocean while Clark remained in charge of the camp. In the afternoon of the 15th, after the wind abated, Clark set out with the canoes. Fighting the waves for about one-half a mile, he rounded Point Ellice. He then continued about 2 miles west-northwest to a small sand beach near present-day McGowan, Washington. There, where a small stream ran down from the hills, he made camp. The captains later dubbed it Station Camp.

Table 1. Mouth of the Columbia

The center of the mouth of the Columbia (as projected from the headlands to the north and south of the river's estuary) on the following maps is shown at the following coordinates:

Map Date Latitude, Longitude Gt. Circle Initial Azimuth* Statute Miles*
Nicholas King 1803 46˚15'N, 123˚45'W 088 12.4 mi 
William Clark 1805 46˚15'N, 123˚36'W 089˚ 19.6 mi
Lewis and Clark 1806 46˚20'N, 123˚36'W 072˚ 20.5 mi
Robert Frazer 1807 46˚50'N, 125˚00'W 311˚ 62.4 mi
William Clark 1810 6˚15'N, 124˚54'W 271˚ 42.7 mi
Lewis and Clark 1814 46˚20'N, 124˚54'W 278˚ 43.1 mi
present-day   46˚15'N, 124˚00'W***    

*Initial heading from the mid-point between Point Adams and Cape Disappointment.
** Great Circle distance from mid-point between Point Adams and Cape Disappointment
*** Coordinates are for the mid-point between Point Adams and Cape Disappoint as shown on U.S. Geological Survey 1:24,000 map; 5.7 miles apart.

Table 2. Celestial Observations Made at Station Camp

Clouds, fog and rain prevailed over clear skies while the expedition remained at Station Camp. On those few days when weather permitted, however, the captains took celestial observations. These were the last observations they obtained in 1805, and were the only ones they made for longitude on the coast.

The following are the observations that they recorded while at Station Camp November 15—24, 1805; all data are from Clark:

Map Date Latitude, Longitude Gt. Circle Initial Azimuth* Statute Miles*
Nicholas King 1803 46˚15'N, 123˚45'W 088 12.4 mi 
William Clark 1805 46˚15'N, 123˚36'W 089˚ 19.6 mi
Lewis and Clark 1806 46˚20'N, 123˚36'W 072˚ 20.5 mi
Robert Frazer 1807 46˚50'N, 125˚00'W 311˚ 62.4 mi
William Clark 1810 6˚15'N, 124˚54'W 271˚ 42.7 mi
Lewis and Clark 1814 46˚20'N, 124˚54'W 278˚ 43.1 mi
present-day   46˚15'N, 124˚00'W***    

The results of these observations are discussed in the order given below:

  1. Latitude
  2. Chronometer Error
  3. Longitude
  4. Magnetic Declination—Variation of the Needle

1. Refraction has the apparent effect of reducing the earth's curvature. A common equation for the combined effects of earth's curvature and refraction, in feet, is: 0.574 x mile. Example: distance 20 miles; 0.574 x 202 = 0.574 x 400 = 230 feet. This means that, at a distance of 20 miles, an object would have to rise at least 230 feet above the eye of the observer to be seen. The inverse of this equation is: Equation: The square root of h divided by 0.574 = miles to horizon. Example: eye height 5.5 feet; 5.5 ÷ 0.574 = 9.582, take the square root of 9.582 = 3.1 miles. This means that for an observer whose eye is 5.5 feet above the ground the true horizon is 3.1 miles away.

The effect of refraction is dependant principally upon the temperature and density of the air between the object viewed and the observer. An air mass of anomalous temperature or density sometimes can form a lens that will produce a mirage in which objects that are below the horizon appear to be elevated above it. Given the prevalent weather conditions on November 7, 1805 and the distance to the ocean, however, this situation would have been most unlikely.

2. The hills to the north were near Point Ellice, Washington (the highest is more than 1100 feet above sea level); those to the south were just east of Astoria, Oregon (the highest is more than 600 feet above sea level).

Funded in part by a grant from the National Park Service's Challenge-Cost Share Program.