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    Image Title  Abstract Category Last Updated
    Benchmarks Benchmarks are survey markers that provide a point of particular elevation used as a reference for determining elevations of other points in a survey. They are used by surveyors, engineers, planners, and contractors for establishing elevations for planning, designing, and/or construction of various projects.The City of Portland is responsible for establishing and maintaining a network of benchmarks throughout the city, each having a known elevation expressed in feet in the City of Portland’s own datum (established in 1896). Most of the City of Portland’s Benchmarks are brass disks about 2 ½" in diameter, and all are marked "City of Portland Bench Mark No. nnnn " and usually set in the curbs of streets. Occasionally you’ll see larger disks of 3 ¾" diameter which are "Class A" monuments, and some benchmarks are set in retaining walls, bridge wing walls, culvert headwalls, concrete steps, or wherever the most stable and accessible placement was determined to be for a specific location. You might also see benchmarks similar to those of the City of Portland’s but with another governmental agency’s or private firm’s name stamped on it. Occasionally the City of Portland Benchmark Book will refer to these monuments and provide elevations, but more often you’ll have to contact the appropriate institution for more information. The benchmark numbers the City assigned to outside agency monuments are for indexing purposes only; PDOT does not stamp a City of Portland benchmark number on other agencies' monuments. Survey 12/13/18 02:27 PM
    brass_screws_pdx Survey 12/13/18 02:31 PM
    pdot_survey_projects_pdx Survey 12/13/18 03:09 PM
    plss_sections_clarkco This data is maintained by and obtained from Clark County, WA GIS. Click the link above to view the Clark County GIS metadata for this dataset. Survey 10/18/18 04:27 PM
    Portland Adminstrative Quadrants Polygons dividing the city into 5 administrative sections. (SE, NE, N, NW, SW) Survey 02/24/03 10:14 AM
    Portland PLSS Sections PLSS Section boundaries for the Portland area. Survey 07/30/02 02:09 PM
    Portland Quarter-Section Index PLSS index of quarter sections for Portland Survey 12/26/01 11:15 AM
    Public Land Survey Townships (Clark County, WA) This data is maintained by and obtained from Clark County, WA GIS. Click the link above to view the Clark County GIS metadata for this dataset. Survey 10/13/11 04:47 PM
    quarter_section_metro This data is maintained by and obtained from Metro GIS. Click the link above to view the Metro GIS metadata for this dataset. Survey 11/09/18 08:55 PM
    quarter_sections_clarkco This data is maintained by and obtained from Clark County, WA GIS. Click the link above to view the Clark County GIS metadata for this dataset. Survey 10/18/18 04:31 PM

       
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