Do it. Handwritten letters are greatly appreciated. A lot of departments around here have websites that have a drop down for commending officers and one for complaining on an officer.

A personal letter of thanks is always appreciated. Of all the awards I've received, I value these the most. My personal favorite of mine was a 80+ year old woman, who after being the victim of a strong armed robbery, wrote a letter on a thank you card when we recovered a rosary beat set that had been in her family for 4 generations.

I think it's a great idea.

Absolutely, it is always welcome to get positive feed back.

I've called a Police Chief about my interaction with a rookie officer about 25 years ago. The officer was very polite and professional. It was a Inspection Sticker check point. (my sticker was good)
I called the Chief and told him how nice and professional the young officer was and he was an asset to the dept.
The Chief said he would put a letter in his file and thanked me.
About 5 years later the young officer was working at detail and I happened to be there. He said you're the one that call my Chief.
We have been friends since and a couple years ago the young officer retired as the Chief of Police for that dept.

I've called two Sheriffs about positive interactions with a couple of their Deputies. They got letters in their files too.
I believe in letting the bosses know when their people are doing a good job.

Well, sadly, the idea has been shelved. I wrote and printed the note, with the intent to deliver yesterday.

However, I asked a friend (who happened to be with me during the interaction) to peer-review it. He liked what I wrote, and agreed that things like that need to be done. He ultimately discouraged me though, and I agree with his outlook.

We were engaged by the deputy at the edge of private land that we have permission to use for recreation. My friend serves as the connection to the property owner, and he said the owner would prefer to minimize any sort of LE interactions; good or bad.

People can get weird about their land; I respect their right to do so. That being said, I opted to (perhaps selfishly) prioritize the relationship with the land owner, and "let sleeping dogs lie". The napping dog wasn't a bad one, but, in the long run, it's better to let him rest.

I appreciate everyone's feedback, and I'll certainly renew my effort, when another relevant opportunity arises.