s_SoNick
So Tallgrass Drive comes off of 13th St to the South and heads North to meet 17th Street. Currently 17th Street is mapped as heading East from Copper Creek Court then bending to the South to meet Tallgrass Drive.

Approximately where I placed the marker there is a street sign saying it's the intersection of 17th Street and Tallgrass Drive. While I was driving it looked like a pretty clear cutoff point for each road, but as noted in my original comment both the current map and my GPS trace show a gentler curve here, making it hard to know where exactly that intersection is without checking on the ground again.

I don't recall the name of the road with no name to the West; I believe there's a street sign for it, but I'll need to head out there again to check it.  The road definitely branches off of 17th Street, though. Thanks for the reminder to check it!