Is it the Dead Tracks hitting Yellowstone Boulevard at a sharp angle, or vise versa? Since the tracks closely parallel the path of nearby Woodhaven Boulevard, and strike most other crossings at a more or less 90 degree angle, I'd have to point to Yellowstone as the arch angler here. The 1st shot points west towards Woodhaven Boulevard, and the 2nd southeast towards Groton and Fleet Streets.
The flora is much more intense atop the northwest bound tracks, which makes for a terribly perilous situation, since this one, out of all the other overpasses along this line, has absolutely no barrier preventing the unwary from falling down onto the street. I've said elsewhere on this site, please do not take this display as encouragement to go up here, or down, depending on where you'd be entering from. One slip on a protruding branch or vine, and there are plenty of both, and you are as dead as the tracks.
As for Yellowstone Boulevard, like most irregular roadways cutting across Queens at wild angles, like welts on a whipped back, it is the present day incarnation of a much older trailway, although I've been too lazy to look its particular history up. Exactly what yellow stone it was named for, I have no idea. It certainly wasn't gold, or even pyrite. Further to the northeast, on the other side of Queens Boulevard, Yellowstone Boulevard was the hangout locale for a group of rockers who eventually became the Ramones. Of course, Joey Ramone passed away not more than a few weeks prior to this writing.
Back in the 1970s, a little playground park, not surprisingly called Yellowstone Park, was the main hangout where the heavy metal type teens, assorted burnouts and burnout-wannabbees of Forest Hills, Corona and Rego Park used to hang out and get stoned; Yellow Stoned. I'm sure they still do. To the south and west, Yellowstone runs across Woodhaven straight into another ancient, irregular angling artery called Cooper Avenue, which prior to the building of the Interboro (Now Jackie Robinson) Pkwy, was the main route into east central Brooklyn from here. Believe me, on particularly bad hair days for the Jackie, Cooper still is.