oregon foreclosures

What state has jurisdiction over a debt collection that occured from a foreclosed 2nd mortgage?
The house in Las Vegas, NV was foreclosed with a 1st and 2nd mortgage.
The debt collector collecting for the 2nd mortgage and is located in North Carolina.
After the foreclosure I moved to South Carolina and obtained a PO Box. The debt collector sent the letter to that PO Box in SC.
I currently work construction to make ends meet and live in Washington State.
I have an Oregon Drivers License because I use a family members address that is more stationary then I am.
Thanks in advance for your answers!
I’m not trying to avoid the collection.
I just want to know what State has jurisdiction so I know what laws apply and where to seek legal advice. Also,
I should have been more clear. The 1st mortgage was foreclosed and completed it’s full process.
The 2nd mortgage has now been sold to collections. My question is in regards to the 2nd mortgage that has been sold to collection only.
You cannot avoid legal action for the difference between what was owed and what the bank sold the home for. They have the legal right to sue you for the difference and will use whatever means they have to track you down. You can’t just avoid answering their requests just becuase you live in a different state.
