“From the northern reaches of Vestland to Thyatis, and as far east as the mighty Isle of Dawn, TM2 picks up where TM1 ended. TM2 shows the eastern D&D Game Known World and brings new facts about traveling costs, rates of exchange, universities, geopolitical intelligence, and more!

All this comes in 8-miles per hex Gazetteer style, on an impressive 36″ by 57″, highly detailed, full-color map.”

The Known World of Dungeons & Dragons was detailed in a series of Gazetteers. Later – early 90s – the classic campaign setting would be known as Mystara.

The Eastern Countries Trail Map (TM2)

1989 … TSR 9404 … ISBN 0880387831

Trail Maps in the shop

Check eBay

DD-TM2 full
This map is huge! 36″ by 57″. That’s almost five feet tall in the long dimension. Here’s a photo of me with the map for scale.
DD-TM1 b
DD-TM1 b back
DD-TM2 detail 1
Rockhome: The Dwarves
DD-TM2 detail 2
Empire of Thyatis
DD-TM2 detail 3
Map legend
DD-TM2 detail 4
Medical Advisory
DD-TM2 detail 5
Imperial Geopolitical Intelligence
DD-TM2 detail 6
Minrothad Guilds
DD-TM2 detail 7
Province of Redstone

EDIT Oct 2019

I found an eye-catching ad in Dragon Magazine #149 (Sept 1989) showcasing their Trail Maps.

Dragon 149 - Trail Maps ad

See Also: 

City of Waterdeep Trail Map (1989): TSR’s Most Misleading Title?
D&D Challenger Series DM Screen and Adventure: Escape From Thunder Rift (1993)
Known World to Hollow World: Atruaghin’s Mystical Conveyor in D&D GAZ14
HUGE WATERDEEP MAP from Forgotten Realms City System: Wayne-sized
Gazetteers!