15 Professional Land Surveyors of Oregon | www.plso.org Featured Article in 1853. From 1864 to 1868 he was the Marion County Surveyor.) The survey was made and the viewer's report in favor of an “excellent roadway” was made to the Marion County Commissioners in August of 1874. The general route started on the east bank of the Willamette River at Salem and then proceeding 83 miles easterly and southeasterly to the summit of the Cascades at what is now known as Minto Pass, about 3 miles northeast of Three Fingered Jack and about 3 miles southeast of Marion Lake. During the viewing and surveying of the route, and old and deeply worn trail was found leading up to the pass and continuing easterly. That trail gives some support to the Indian tradition of a former native thoroughfare leading down the valley towards Detroit. After the viewing and survey reports, several unknown parties filed articles of incorporation for a company to construct a railroad through the pass. It turned out to be all speculation, but had the effect of weakening public interest in constructing a road, only to see it later destroyed by railroad interests. An association was formed in late 1874, however, to construct a stock trail beginning near Gates and running easterly along the north side of the Santiam. It was completed at a cost of $1,800, and was generally always within sight or sound of the river. About 3/4 mile west of the Bruno Mountain Bridge (located just west of the former Big Springs Campground) John Minto had to locate his trail on the hillside to get above the cliffs along the north side of the river. The route along the steep hillside crossed a talus slope (picture 3). With the advent of lidar (light detection and ranging), it is now possible to capture an image of the ground even if it's covered with dense timber. A specially equipped plane flies over the area and emits laser pulses downward which then bounce back to a receiver in the plane. Some of them bounce off tree tops while others bounce off the ground. The signal strength determines which is which. The resulting lidar image in this case is shown in picture 2 and was taken about 5,000 feet vertically above the site. It is amazing that Minto's 2-foot wide trail on the hillside is still visible after 148 years. William Bushey, the U.S. Deputy Surveyor mentioned near the beginning of this article, noted settlers within Township 10 South, Range 7 East in his field notes as 3 WAYS OF SEEING Below are three images of the same portion of the Minto Trail using different technology: aerial photo imaging, lidar imaging, and traditional cartography. Aerial photo image of a portion of the Minto Trail. Match the numbers on this photo with the numbered photos on page 16 for a ground view. Using lidar (light detection and ranging), it is possible to capture an image of the ground showing Minto’s trail, even when it’s covered with dense timber. A traditional map that illustrates the same portion of the Minto Trail shown above. continues
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