The 103-year-old non-profit facility, which sits on 16 acres, is a no-kill shelter and home to about 35 dogs and 62 cats.
Hennessey said they shelter was contacted a few months ago by the Treasury.
"It was something that was unknown to all of us," said Jodi Button, executive director of the shelter. The money was a gift in the form of stock. "We were kind of shocked. It is a particularly nice sum."
It is not uncommon for organizations to be unaware of the unclaimed money, said Michael Smith, spokesman for the Treasury. "They may not have been notified."
The Treasury has about 1.9 billion in unclaimed property.
There is no obligation for the holder or organization that has the property to report it to the owner, before they are obligated to report it to the treasury, Smith said.
Organizations that have unclaimed property simply may not have been notified about the funds. The money could have been lost in record keeping or left in safe deposit boxes during bank mergers. It could be in the form of a lost paycheck, or gone missing for some other reason.
Smith did not know why the shelter's funds went unclaimed.
The state has been reaching out to non-profits, school districts and municipal governments to let them know about the cash, Smith said. In June, Montgomery County received more than $49,000 back from a combination of payable checks, refunds, rebates and escrow accounts that were never cashed, according to the Treasury.
"We have estimated people have a one in 10 chance of finding property," said Smith. The average claim is about $1,200, he said.
To check for unclaimed property contact 1-800-222-2046; or, search http://www.patreasury.gov/unclaimed/search.html.
Contact staff writer Mari A. Schaefer at 610-892-9149, firstname.lastname@example.org or @MariSchaefer on Twitter.