[Freeware] Agua Caliente Springs (L54)

Whilst it is not exactly what you are after, you might be interested in our Arrows Across America project which has reconstructed 4500 miles of US Air Mail navigation routes for the late 1920s.

We have placed arrow and beacon markers in their correct locations every ten miles along the Contract Air Mail (CAM) routes, along with historically accurate Intermediate Landing Fields (ILFs).

For some of the ILFs we have had to remove the modern world (in one case a golf course) to place them.