If one believes I drew this line correctly (It appeared to me that the track begins 4 lots south of McCleary Playground on McGee.
The mapping program says 146M
Whatever numbers you or I come up with in a mapping program, it's extraordinarily unlikely that they would build anything approaching a 146m platform. Even 125 seems excessive. Given that one of their diagrams is already provably incorrect, it's probably not worth any extra thought right now.
The important thing is that they've found a good location to put the platforms that won't interfere with any buildings or parks.