My father died in January. We are settling part of the estate and I need to send my nephew in North Carolina 24K, I live in Michigan.
The thought of sending any kind of check that large through the USPS, Fed Ex or UPS kind of scares me.
What other options do I have?

Direct transfer bank to bank.

Wire transfer from your bank account to his.

Bank wire transfer.

As stated, wire transfer.

The check should be drawn on an estate or trust account. We (my law office) routinely send small to moderate sized checks to beneficiaries and the IRS via USPS and UPS.

Sometimes we wire the funds. The last money transfer we did we had the banks on each end arrange for an ACH transfer. That was super simple.

ACH transfer.

I was gonna say $1s and $5s but a wire makes more sense.

What's the concern about sending a check? In the unlikely event that it was lost or stolen you can deal with that easily.
Should take a few days then confirm receipt with tracking or a phone call. Then he deposits the check. No big deal. There will be a record to the payment and deposit. The other option is a wire transfer directly to his account. Costs about $35 at most banks.
Based on the title of the post I thought you were considering a large amount of greenbacks. That I wouldn't do.

Electronic transfer.

When I settled my Dad's estate and I was ready to disperse the funds the bank holding the funds did all the work. I only needed the account and routing numbers for my out of town brothers. Fast, secure and easy. They already had his death cert and my executorship papers on file and charged nothing for the service.

USPS Priority Flat Rate Envelope with signature confirmation.

I am executor for my deceased parents. I sent larger amounts to my brother via back wire transfer.

I agree wire- you don't want that much cash getting lost.

Easy way: Direct Xfer

Or

Find a bank in your town that has a bank in his town.

Both put your names on same account,
Deposit the money and he takes it out at his leisure

I like the way Bendable thinks...no need to pay the bank for them to wire money!

If you (sender) have a bank near you that he (nephew) uses and has an account, just go make a deposit to the nephews account.

If not, then priority mail (USPS) or FEDEX a letter wi5 a check that is signature required and traceable...

B2B mail checks thats size and more routinely.

Perfect for the season. 12 days of Venmo.
They let you do $2000 a day.

Seriously. Worth the money to track the wire transfer. Yes check is nice but by the time add time to get it and then the cost and time to go send it, well worth the wire fee. Also the save the nephew the hassle of heading to the bank and make a deposit. Needing various ids and then his bank hold the money until the clear the check.

Mail a smaller check each day until you reach $24k.
(2) 12k+12k
(3) 8k+8k+8k
(4) 6k+6k+6k+6k
(5) 5k+5k+5k+5k+4k
(6) 4k+4k+4k+4k+4k+4k

Or make it the X days until Christmas!

USPS priority mail and cashier's check (if free), otherwise bankwire.

Or, like my brother did when he sold his apartment in Buenos Aires, Argentina and put the proceeds down on a new house outside the city....hired an armored truck to move the cash (nobody does checks for property sales there).

I agree with those suggesting wire, ACH, or just mailing a check. The irony is that a wire is not only most likely the easiest and most secure, it's also likely cheaper than a certified/official/cashier check and shipping.