How Do I Get My Son Off Drugs?

I need to get my son admitted into a drug rehab, and I want to know how I could find one that would be right for him.

I have a 16 year old son, we lost his dad 3 years ago & it is still very difficult. We tried counseling, but noone in our area deals with “grief counseling”. I lose it in spurts, but deal pretty well. My son has down right depression binges… he hates visiting the grave & seems almost angry that his dad died. Anyone with advice? Is this a normal response almost 3 years after the fact?
Wonderful advice from most of you… I guess some of you misunderstood… I NEVER force him to go to the grave site. I have offered to take him if it would help, when he says NO, that’s it. I don’t mention it until he brings it up, then I re-offer. I will need to search for different counseling centers, must of you suggest he still needs outside help & Thank-you! I understand my grief is different & I am coping quite well, he & his dad were best buddies as well as extremely close dad & Son. I appreciate all your responses!

I’m going to send my son to a drug rehab, and I want to know how I can get information about them.