What kind of directions are these?

So I'm reading a story about the new Habitat for Humanity Home Improvement store in south Seattle, and I'm thinking "Gee, I don't recognize that address. Wonder where it is?" And then I see the link for "directions". I click on it and, for some reason, start reading the "From South" set:

From South: Head North on I-5, take Tukwila Exit to WA-599. Highway 599 will connect into Highway 99. Take Highway 99 towards East Marginal Way . Take left onto East Marginal Way. Turn left onto Idaho Street use left hand turn lane. Turn right onto unmarked street before the Fiberlay building. Follow road and turn left on S Nevada Street

Is it just me, or does that sound like either the directions to a speakeasy or a street fight? "Turn right onto unmarked street"? WTF?