From milepost 0.0 (at Broadway and Washington) a traveler continued three blocks eastward to 4th Avenue, took 4th north to Burnside and turned east on Burnside to 39th Avenue, then turned south to Stark Street. According to Drinkhall's notes, Stark Street (Baseline Road) was the route to reach the Columbia River Highway.
Clarence E. Mershon. The Columbia River Highway: From the Sea to the Wheat Fields of Eastern Oregon. Portland: Guardian Peaks Enterprises. 2006. 1st Edition. (51)
1916 Troutdale - Detail
Stark Street Viaduct, West End (2014)
Stark / Baseline. Historic Columbia River Highway. Oregon. January 6, 2014
CLICK ON IMAGE TO ENLARGE
Auto Club, Dabney Park, Springdale - CLICK ON IMAGE TO ENLARGE
Having ascertained these facts the writer made several trips over the proposed route of the highway, and it was found that from the western boundary of the county, passing through the city of Portland to Chanticleer Inn, 22 miles to the east, the existing roads, serving a splendid agricultural section, are for the most part comparatively level, and with the exception of some short and dangerous curves in several places, and steep grades on both approaches to the Sandy River, these roads require but little more than drainage and hard surfacing to make them reasonably good, although, of course, the location can be improved materially in many places. (Lancaster, 1914 58)
Page 050 - Township 1 S. Range 4 E., Sandy River, Section Line Road Fruit Tract
Atlas: Multnomah County 1927
Metsker Maps 1927
Historic Map Works.
SE Stark Street had its early beginnings as an old wagon road called Base Line Road. The historic street was named for Benjamin Stark (1820-1898), a US senator from Oregon. In the survey of Portland, dated 1852, Stark Street is listed as an original street to downtown Portland. In Jan of 1892, a section of Base Line Rd was changed to Stark Street. This included all roadway from the east bank of the Willamette River to the Lone Fir Cemetery (21st Ave). In 1912, the Stark Street name was extended out to Montavilla (75th). It appears that for a time, the roadway went by both names. In the early 1900's, it was called Stark Street within the Portland City limits and Base Line from the edge of the city out to the Sandy River. In 1920, an attempt was made to change the name of Stark Street to Wall Street. This idea was fought and ultimately defeated. The building of the Morrison Bridge in 1887 and the removal of tolls in 1895 put an end to the Stark Street Ferry in 1895. In 1900, SE Stark Street was a gravel road and Base Line was a dirt road. Stark Street has undergone many improvements (widening) over the years. The inner portion of Stark was paved in 1915. The street was widened to a two-lane road and paved from 82nd out to Burnside St (near Gresham) in 1929. (http://starkstreetmarkers.blogspot.com/2008/05/blog-post.html)
Apparently, this route was mapped as Alt. US 30 for a period of time... Not sure when that designation was removed.