As I mentioned a few days ago, I found the remnants of Double Bow Knot Boulevard in Lookout Mountain Park, just a short walk from where I live. 3940dxer had posted the following postcard view at page 325 of this thread without being able to identify where this street was:
Here is a current view I took a couple of days ago from about the same place:
As you can see, 100 years of vegetation serves to block the clear sight lines seen in the postcard. But particularly telling, I think, is the shape of the hill in the middle distance separating Lookout Mountain Avenue (on the near side) from Stanley Hills Drive (on the far side). Laurel Canyon can be distantly seen in the left-center of both views.
On foot, you can follow the switchbacks of Double Bow Knot Boulevard down to lower Crescent Drive (would not advise street shoes for this, though).
Double Bow Knot Boulevard was an important street for the developers, as it led from Laurel Canyon to Wulff's Peak - the high point in this part of the Hollywood Hills which was a tourist destination in early twentieth century . This land was sold in 1913 by the Lookout Mountain Park, Land, and Water Company to E.L. Doheny and is in the northern-most extremity of the City of Beverly Hills. Today, it is occupied by water tanks at the end of Walker Drive.
The LA Times of 21 August 1913 stated:
"Wulff's Peak, which presents a rugged and precipitous face to the mesa that spreads south from the mountain range, is accessible by a paved roadway that wends through the picturesque Laurel Canyon and Wonderland Valley and climbs the mountain sides in a double bowknot in a 5% grade. The route is familiar to thousands of automobilists who have traversed it to gain the splendid view which it affords of the surrounding country."
"The 'Belvedere of America' is a term which has been aptly applied to the peak, from which Doheny cannot only survey every part of his ranch, but obtain vistas which are comparable to those of the famed counterpart in Europe. From Wulff's Peak one can see on a clear day far to the east, Monrovia and Santa Ana. To the west, beyond the mountain range, is spread out the vast expanse of the sea and the Channel Islands, far off shore, may be sighted. On the north lies the beautiful San Fernando Valley, which spreads out in a grand panorama to the horizon and the higher mountains."
In the next few weeks I hope to add to and clarify what has already been posted by 3940dxer about this area.