My mother has recently passed away. Months ago she told me she opened an Irrevocable Trust in my name, and one for my sister as well. I can not locate any paperwork and went to 2 local banks that she used, and have had no luck finding these accounts. I know they were opened within the year so she has not received the 1099 from the IRS yet. Is the 1099 my only way to locate the accounts? What will the 1099 tell me (what bank they were issued from)? Is an Irrevocable Trust something she could have opened online or would that be done in person? Any advice how I go about locating these accounts with nothing to work from?

The 1099 does not come from the IRS, the bank where they were set up will send out documents.

Also a trust can be set up though an attorney to be done at the time of death with proceeds though places like insurance payouts.

Also a trust can be set up, but have no money ( they hope to add money latter)

But no, you watch their mail for the next year or so, check all of the email and more to see if you see anything.
If she had an attorney talk with them, assuming this is a small town, you may contact all the local attorneys to see if she was a client.

Also where did the money come from to go into that account, was there large withdrawals from savings or from IRA's in the last year, then you could trace the money