The park was out of bounds to visitors from March 25 when a nationwide lockdown was imposed.
The government has been encouraging Thai people to travel to famous tourist attractions during holidays and has even offered incentives.
Phu Kradueng is one of the most famous national parks, spread over 217,576 rai (34,800 hectares), with an abundance of flora and fauna attractions.
The geographical diversity of the park includes cliffs, waterfall, field and forest, which draw domestic and international visitors throughout the year.