First as seen above, this is where to go west of Prince. The mainlines tuck into Stretcher's Neck tunnel, then spiral down in a helix under the wide spot of the layout. Whether I simply tuck the mains in behind scenery on the branchline portion of the layout, or have enough helix to make an entire lower deck to include Thayer and surroundings is yet to be decided. But in any case, it comes back up to meet another branch at Thurmond as seen below. Whether the Piney Creek branch (Prince) and Loup Creek branch (Thurmond) will connect is also yet to be determined. In some way, there could be shared staging.
Beyond this, I'd love to include a reasonable representation of Meadow Creek (plus its branch if it all possible) and Hinton... good luck right? I'm running out of room.