About 400 people were in the first group to climb Phu Kradueng on Monday morning after the popular national park reopened two weeks after a visitor walking a trail was killed by a wild elephant.
Phu Kradueng was closed on Dec 13 after a tourist was killed by a tusker in musth on Dec 11.
The first group arrived at the entrance about 5am on Monday and were allowed in an hour later, the park said.
Phu Kradeung is open to climbers from 6am-1pm. The park in Phu Kradueng district in Loei province is one of the most popular destinations for tourists during long weekends, especially the new year holiday when the weather on the mountain turns cold.
One of the highlights is to watch the sunrise at Pha Nok Aen, a cliff with a rock terrace about two kilometres from the tourist service centre.
However, the park said on its Facebook post that the cliff is one of the places and trails still temporarily closed for the safety of visitors. Other closed routes include all waterfalls and another popular trail from Lang pae, a flat area on the mountain top, to another cliff, Pha Mak Duk, to witness the sunset, which is about 2.5 kilometres from the service centre.
"Please reconsider allowing us to see the sunset," Facebook user KaeKae Phitchar wrote on the social media page.
"I'd rather wait for a 100% reopening," Pong Ttom wrote.