M1 - Deer Island, US 30
In Deer Island, milepost 34.
Campsite of the Lewis & Clark Expedition, 1805 and 1806.

M2 - Thomas McKay, US 30
Scappoose, near Old Portland Road.
Thomas McKay, Hudson's Bay Company fur trader and operative, died near here.

M3 - Joseph L. Meek, US 26
1.5 miles east of North Plains.
The land claim of Meek, mountain man, who helped found the Oregon Provisional Government.

M4 - Willamette Stone, Skyline Blvd.
W. Burnside Street to Skyline Blvd., Willamette Stone State Park, Portland.
Site of the first surveyor's base mark in Pacific Northwest.

M5 - Troutdale, off I-84
Exit 17 to the Troutdale Chamber of Commerce, 338 E. Historic Columbia River Hwy.
Pioneer community settled in the 1850's.

M6 - Sandy River Bridge, off I-84
Exit 17 to the Historic Columbia River Highway, at the east end of the Troutdale Bridge.
Boat crew of HMS Chatham sights river and names Mt. Hood from here in 1792. How Sandy River received its name.

M8 - Bonneville, off I-84
Exit 40, near RR underpass into Bonneville Damn Park.
Named for famed explorer and Army officer, Captain Benjamin Bonneville, who came to the 'Oregon Country' in 1832.

M9 - Beacon Rock, off I-84
Exit 40, in Bonneville Dam Park.
Prominent geographic feature named by Lewis & Clark in 1805.

M10 - Laurel Hill, US 26
Two miles west of Government Camp.
Site of the most treacherous descent of the Oregon Trail through Cascade Mountains.

M11 - Oregon City, OR 99E
Parking area overlooking the falls.
Honors Dr. McLoughlin, pioneers, early Oregon government and many firsts in Oregon.

M12 - Oregon City Falls, OR 99E
Parking area overlooking the falls.
Notes uses of site ranging from early Indian salmon fishing village to first long-distance hydroelectric power generation in the United States.

M13 - Willamette Falls Locks, I-205
West Linn viewpoint, eastbound at milepost 7.7.
Series of five locks with a total lift of 50.2 feet opened in 1873.

M14 - Willamette Falls, I-205
West Linn viewpoint, eastbound at milepost 7.7.
The falls were originally a Native American fishing site and later became the power source for numerous mills and electricity generation.

M15 - Dr. John McLoughlin, I-205
West Linn viewpoint, eastbound at milepost 7.7.
Dr. John McLoughlin was the Chief Factor of the Hudson's Bay Company and founder of Oregon City.

M16 - George Abernathy, I-205
West Linn viewpoint, eastbound at milepost 7.7.
George Abernathy was the first Provisional Governor of the Oregon Country.