I'm looking for a GPS for my loved one. Are any of the tracking devices reliable?

Try your local sheriff's department. Ours has a program called Operation Lifesaver. It's a bracelet that they wear around their wrist or ankle and has a GPS. It cost $10.00 per month to monitor and there are some conditions. I hope this helps you. You can Google the program.

I'm sure there is a product out there that would work for you. I have a small device on my dog's collar (she's a runner).  I get an email and text if she leaves our property. I can then track her on my phone. I have it set up to use at two locations because we go to our RV on weekends. When we leave our house I get a text that she has left the house and when we get to the RV I get a text that she is at the RV. It has a small monthly fee and is very user friendly.
If you google trackers for Alzheimer's patients you will get some ideas. The Alzhermers.net site has suggestions
www.alzheimers.net/8-8-14-location-devices-dementia/ Good Luck!

There are phones that you can track if your loved one carries the phone all the time that might work.
My Husband wandered a few times and the Police suggested that I contact the Mental Health Department where I am, they have a program called Care Trak and it is a watch like device that is worn on the wrist. A profile is done of the person, a photo is taken and this info is given to the police. When the person goes missing you call 911, tell the dispatcher that they are on Care Trak. The police set up a "command station" with all the info they have and an officer goes around in the car with an antenna that is set up to pick up the signal from the device. I was told this is better than GPS as the signal does not get lost if the person enters an area where signals are not clear.
the person with the device does have to be under 24 hour watch though. You can not leave them alone to go to the store, to work. It is for anyone that can not easily communicate. A person with dementia, autism are the perfect candidates.
There is also the collars that are put on dogs, you can set an acceptable range and you will be sent an alert if the collar is past the pre set boundary. I think the device can be removed from a collar and put on a belt, key chain.
And I have seen tracking devices that are placed in shoes.
Some of these have a monthly cost.
The Care Trak, I had to check the battery daily, log the checks and we had to go to the office 1 time a month to have the battery changed.

Easiest thing would be to check with your local police or county sheriff. If nothing else they would probably like to know that there is a potential that you may be calling for a wandering adult with dementia. I have found that they are nothing but helpful and understanding.

We just experienced my father-in-law (93 yrs. old) getting lost on our property. We have 13 1/2 acres and some of it is undeveloped. The only reason we knew he was missing was because we have cameras set up at the house and can monitor his where abouts. My mother-in-law, who is 92 and wheelchair bound, was freaking out and we didn't see him on any of the cameras. My husband went over to see what was going on and realized his dad was missing. We are talking about 10 minutes of time had passed when my mil started freaking out. We searched the parts of the property that we could and when we realized we couldn't find him, we call 911. 3 1/2 hours later, he was found in the back corner of the property in a wooded area by a police dog. Thank God for these tracking dogs!!! I applaud our Sheriff department for their compassion during those trying hours. FIL was confused and had wandered into the wooded area and fallen down and couldn't get up. If it hadn't been for the cameras, we wouldn't have known there was an issue.
The cameras cost about $40 each and are easy to hook up to your WIFI. There is an app for your phone and you can check on them anytime. It swivels 360, has sound and motion detection (optional). Great product!!

Amazon
TENVIS HD IP Camera - Wireless IP Camera with Two-way Audio, Night Vision Camera, 2.4GHz & 720P Camera for Pet Baby Monitor, Home Security Camera Motion Detection Indoor Camera with Micro SD Card Slot.

One more thing. We are going to put door knob covers (the one for baby protection) on the doors leading outside. I don't think he will be able to figure out how to open the door with them on. He and my Mil have dementia and are pretty clueless.

It looks as if many devices are designed to summon outside aid if one falls rather than simply to provide the person's location to a responsible family member. It would seem reasonable that if a GPS could be somewhere on or inside the elder's shoe it would "have" to be worn unless the person wanders outside barefoot or without shoes.

My husband wears a GPS watch that I got through the Alzheimer's Association. It alerts you when he gets more than 200 yards from the base station. I can also look up on computer where he is in case he does manage to "escape." Google your local Alzheimer's Association store.

Automatic Fall Detection For Seniors

Most traditional medical alert monitoring systems rely on a pendant or button that your loved one must press in order to call for help. These systems are highly effective and save lives every day.

Some seniors, though, are at a higher risk of falling than others. There is the possibility that when your loved one falls, they may be unable to press their medical alert button to call for help. This is where Automatic Fall Detection comes in.
From the company called "Medical Guardian"--
Automatic fall detection technology is a newcomer to the medical alert monitoring industry and it’s not without some controversy, since they can’t detect 100% of all falls. Read our most frequently asked questions in regards to medical alert devices with fall detection to learn more.

Some Alzheimer's Association also have locator services with law enforcement. A chip is embedded in a sneaker. If the LO strays from the home, law enforcement can locate them via the chip in the shoe and deploy assistance. There is no charge to the family.

PS. The watch is too complicated for them to remove.