Welcome back. In my last discourse I mentioned I was working my way around the center of the Greater Portland area clockwise. This means our next destination, as we cross the Mighty Columbia going south, is eastern Multnomah County, followed by Clackamas.
Here's what I know.
Eastern Multnomah County
As one travels east, past Gresham, Fairview, and Troutdale, the metagrid proceeds faithfully to the crest of the Cascades. Multnomah, for its being a narrow bit of land, as all Valley counties that exist on the east side of the great Willamette, terminate at the crest of the Cascades.
The division line, NE/SE, on the ground, follows Burnside Street faithfully eastbound until you get to 181st Avenue, in the Rockwood area. Burnside then begins a curve south, leaving the baseline. It defines quite a graceful curve along the north and east areas of Gresham, to become SE Burnside Road, then NW Burnside Road as we cross into the Gresham address grid (at about the 20200 Block), NE Burnside Road as we cross the N Main Avenue address baseline for Gresham, then SE Burnside Road as the SE 1st Street baseline is crossed, the road name finally terminating at the big Burnside/E Powell Blvd/Hwy 26 junction in eastern Gresham.
From 181st east to the edge, then, the division line becomes virtual rather than actual but continues its straight surveyed course. The neighborhood centering on SE 223rd Avenue and Stark Street, in north central Gresham (historically known at Twelvemile), shows how it's dealt with, proceeding south: NE Couch Street, then SE Ankeny, SE Oak, and SE Stark Street. The addresses simply descend to zero and start going up again, and the directionals go from NE to SE with no dividing E street. This is very similar to Washington County in the Aloha area, where SW gives way to NW in many areas without the extension of a dividing street.
The procession is interrupted as one proceeds east by the internal address grids of Troutdale and Gresham (that's for another post), and take up again as you cross the Sandy River. The Springdale and Corbett areas have a scattering of numbered avenues (NE 366th Avenue, for example) but, in this area, numbers give up after that. The NE/SE directional continue for wherever there are developed roads, however. The streets serving the Warren area-that district where the Historic Columbia River Highway touches I-84 east of Troutdale-are prefixed NE, as are few roads on the Oregon side of the Columbia River at Bonneville Dam. Address numbers themselves get correspondingly huge, north of 50000.
Clackamas County wears two systems. They still decrease as one moves toward Portland, at least as one goes north.
Directionally, Clackamas County breaks along a line formed by the Willamette and Clackamas rivers. This divides the County into two uneven chunks.
The north part, that part which contains West Linn, Gladstone, Milwaukie, Happy Valley, Damascus, Sandy, and Government Camp, inherits the address progression of the areas north of it, and in many areas, notably Milwaukie, Damascus, Boring, Sandy and the area between Wilsonville and West Linn, also inherits the numbered Avenue sequence. Downtown Milwaukie contains a SE 21st Avenue, only three blocks from the Willamette, and the road along the Willamette Meridian, which historically was called Meridian Road before development reached out that far (and from which Meridian Park Hospital takes its name) is known today as SW 65th Avenue almost all the way into Wilsonville. The progression of numbered avenues into the Sandy area has already been documented.
The Willamette continues its SE-ward meander south of downtown Lake Oswego. The older parts of Lake O, however, form an interruption in the pattern-it has retained its historic pattern. South of this, outside the city limits and in the North Stafford area, the metagrid reasserts with its 20-to-the-mile blocking. The line that separated zero-hundreds in Portland proper continues, but in the area between that line and West Linn, a new prefix is named: South. To the left of this, SW obtains.
Meanwhile, on the east side, the address progression maintains as an extension of the Portland system. Somwhere east of SE 502nd Avenue, a soft boundary is passed, and all roads have the simplex directional East. Addresses along Highway 26 in the Welches area run past the 68000s, with addresses on the cross streets getting high-we've come quite a bit south-an address such as 68200 E Highway 26 or 24500 E Arrah Wanna Blvd are possible.
Yes, there really is a road out in Wemme/Welches called E Arrah Wanna Blvd. I just love that name.
The practical end of this is Government Camp. Held gridiron-true by township, range, and section lines, east-west addresses reach (some would think) absurdly high ranges (but I love this stuff). The section of E Government Camp Loop going through the GC commercial district wear address in the 88200 to 90200 range. A 92200 Block is defined about one mile east of where Government Camp Loop rejoins Highway 26 going east, but is not likely to be developed as such. North-south addresses in the small cross streets have similarly respectable ranges, about 30500-31000. All streets are still prefixed E.
Turning our attention south of the Clackamas-Willamette line, we find the directional on all roads is S (S Springwater Road, S Hwy 99E (or McLoughlin Blvd)), and a surprising thing; though addresses decrease to the north and west, as we might expect, the origin doesn't seem to be the center of Portland, nor does it seem to be obvious, nor does it even seem to be contained in the system.
The lowest possible address in the South area in the north-south range is the 14000s, this in a near oxbow of the Clackamas River near the 212/224 fork; the lowest possible in the east-west range is the 4000 block, where S Elliott Road crosses the Pudding River, just off S Meridian Road (which follows very close to the Willamette Meridian) from a junction about a mile south from Meridian Road's junction with State Highway 211 (the road that connects Molalla and Woodburn).
But that's not all. The most suprising observation about this area is that address run 10 standard 100-number address blocks to the mile-not 20 as true throughout the rest of the metropolitan area.
Since the addresses align along section lines it should be simple-in principle-to find where zero would be. But, alas, my records are incomplete and my time is up. This will have to wait for another time.