Before land could be purchased from the United States a survey was required. The U.S. Office of the Surveyor General hired Lyman Andrews to survey the area, which included the site of the future business district of West Seattle. He surveyed a six mile by six mile township into 36 one-square-mile sections. It took Andrews about two weeks to complete the survey of the township designated as Township 24 North Range 3 East Willamette Meridian.
On September 26, 1862, Andrews and a crew of four surveyed along a line that eventually became a road called SW Alaska Street. Proceeding west they crossed a 300-foot wide prairie that changed to an alder thicket at 48th Avenue SW. After about a block they started an ascent that continued until they reached a summit at 45th Avenue SW. The land remained level for about six blocks when the crew started to descend. At the bottom they crossed a one-foot-wide stream located at 38th Avenue SW.
In his notes Andrews describes the one-mile stretch between 51st and 35th avenues SW as "Land rolling soil mostly 1st rate. Timber cedar, maple & Fir. Undergrowth Cedar, ash and willow." Although local Indians had crossed this area for millennia, this is the earliest record of Euro-Americans crossing this part of West Seattle.