The map is Hardened Copper Creek Castle - but I must admit, I probably shouldn't have played it. :D I'm not stuck or anything, it's just taking longer than expected with the artifacts I'm using. I'm not at the right level for the other artifacts. But this map has a lot of artifacts to discover, so I'm not too worried.

It's 100% the correct play. Epic TS is really good and the 600+AP is alot at your stage

I second that. Epic TS is a game changer and is absolutely necessary to complete US. It has a 299B county in Virginia that I wiped out in 16 hours using an Inspire Mercenaries to raise the 60B payment and then the epic TS to take it. Trying to raise those armies otherwise would have taken weeks. Also, when you upgrade the TS from epic to legendary, the artifact returns 60% instead of costing 20% (going from 80% to 160%). That really speeds things up! Imagine hitting that 299B county and getting nearly 180B free armies. You probably can complete the map right away after that. Finally, with the epic army camp and epic TS, I reduced my map times by over 40% in the second pass.

I love Epic Triple Strike. :)