As local historian Paul Dorpat writes in “Section lines on Wallingford Hill,”
The meeting of 45th Street and Meridian Avenue began in the forest, when federal surveyors carrying their Gunter chains described — and marked — the future streets as the west (Meridian) and north (45th) borders for the 640 acres of federal land section number 17. That done, the settlers could identify their claims with some precision.
Indeed, King County’s quarter section map covering the intersection shows that (going clockwise) sections 7, 8, 17, and 18 of Township 25 North, Range 4 East, Willamette Meridian, meet there.
This means Meridian Avenue N is named after a meridian, but not the Willamette Meridian (which, once it reaches the latitude of Seattle, is on the Kitsap Peninsula), the Puget Sound Meridian, or the City Standard Meridian. As this overlay map I made shows (see below for the section of the map showing the intersection of 45th and Meridian), Fairview Avenue N follows the same alignment between Denny Way and Valley Street.
Meridian Avenue N begins at N Northlake Way just north of Gas Works Park and goes 1½ miles north to N 55th Street, where it becomes Kenwood Place N. It resumes at Kirkwood Place N just north of N 59th Street, and goes ¼ mile north to E Green Lake Way N. On the north side of the lake, there is a block-long stretch from E Green Lake Drive N to N 75th Street, and a longer, ¾-mile one from N 77th Street to N 92nd Street and North Seattle College. Meridian begins again at the north end of College Way N at N 103rd Street, and goes just under a mile to N 122nd Street, south of Haller Lake. It resumes on the north shore of the lake as a shoreline street end (though not on the city’s official list) and goes a mile north to the city limits at N 145th Street. As with most North Seattle avenues, the name continues into Shoreline, and in this case the arterial street itself keeps going for 3 more miles to the King–Snohomish county line at N 205th Street.