Legal Question in Wills and Trusts in California

If you have a valid POA, is there any reason not to open the account in your father's name?

Presumably the trust paying your father the inheritance is making checks out in his name. A POA is only valid until your father terminates it. While in effect, you owe your father a very high fiduciary duty in handling his money. Co-mingling his funds in an account in your name is a very bad idea.

Use the DPOA, create an account in your father's name to receive the funds - the trustee may be willing to set up a monthly electronics funds transfer so you won't have to deposit checks.

Be sure to consult with your father over what to do with this money. If he wants to sign checks over to you each month (say, for example, he doesn't want an account out there subject to seizure for court ordered restitution), that's legal, but get it in writing. You cannot gift yourself his money with a DPOA unless the DPOA specifically authorizes gifting. Most DPOAs do not do this.