NATIONWIDE – Monday marks the third day hundreds of national park sites will be closed across the country as a result of the government shutdown.

In Texas, of the five UNESCO World Heritage Sites, Missions Concepción, San José, San Juan and Espada are closed. The state-owned Mission Valero or Alamo will remain open.

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Over the weekend, visitors were surprised to find the internationally-recognized historic Spanish colonial missions closed for business in San Antonio.

Nationwide, a third of the more than 400 national park sites across the country are completely closed. Until the shutdown is over, more than 21,000 federal park employees will be furloughed from working.

During the shutdown, only the 3,200 “essential staff” will have the responsibility to manage 80 million acres of national park lands.

Politicians and citizens alike understand the stakes are high to strike a spending deal soon.

"Let's step back from the brink. Let's stop victimizing the American people and get back to work," said Sen. Mitch McConnell.

In 2016, the missions welcomed 1.3 million visitors, pumping $110-million into the local and state economies.