This should work. It's pretty simple method. I cannot test with your sheet as mine is not nearly that large, but you can try it.


I have tested this code with your picture of cells and it works well.
 The reason to use the following code is because it is simple and can save valuable programming time. The SpecialCells Method is reliable if used correctly just like any other programming language and function. It is worth a try and also worth timing with your larger data. 


I hope this helps.

```
 Option Explicit
 
 Sub RunIT()
 'Input range must be the first cell of where the data starts
 GetAllCells Range("A1")
 End Sub
 
 Public Sub GetAllCells(rngInStartingRange As Range)
 Dim strTemp As String
 
 strTemp = Range(rngInStartingRange, rngInStartingRange.SpecialCells(xlLastCell)).Address
 End Sub
```