Here's the notching / routing breakdown:
Donner Pass Tunnel Work Diagram
- Rocklin to Bowman: all tunnels on both the #1 and #2 / stacks use both tracks
- Bowman to Colfax: #2 tunnels untouched, part of unfunded "Phase II" / new CTC crossovers at Bowman and Colfax put EB/WB stacks on the #1
- Colfax to Truckee: all in use tunnels on the #1, #2, and single main / stacks use both tracks