New Caney, Texas - The Koster family was devastated when their beloved four-legged friend Maddie vanished without a trace.

Maddie vanished three and a half years ago in August 2017, just days before Hurricane Harvey hit Texas. The Kosters had just moved to New Caney, and they think the dog ventured outside with a friend who was helping them unpack.

Maddie's owner Rachel Koster told KPRC 2 Click2Houston that the furry pooch just vanished. Everyone looked for the dog, but they couldn't find her.

The Kosters searched for their beloved pet for months, but the trail went cold. "After you search for so long, you just assume the worst," Rachel Koster said.

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Last week, the family's phone rang. Rachel Koster's mother was on the line and told her daughter that she had been contacted by someone who had information about Maddie.

Rachel couldn't believe it: "At first, we thought it might have been a scam..."

Rachel got the stranger's number from her mother and called back.

The stranger turned out to be a volunteer with Lost Dogs of Texas, an organization that helps families find their missing pets.

Rachel Koster found out that Maddie had reappeared in Sugar Land, a town about 50 miles away from New Caney. A volunteer from a different animal rescue organization, Forgotten Pet Advocates, spotted the dog walking along busy streets and posted a picture on social media. Lost Dogs of Texas reached out to the Good Samaritan and helped find the Kosters.

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The animal organization was able to reunite the long-lost dog with its family because the Maddie had a microchip with her family's address.

The family was able to pick up Maddie from the Lost Dogs of Texas shortly after the phone call. The scruffy dog enjoyed all the attention from its beloved family.

Where the small dog disappeared to for the last three years remains a mystery.