Yosemite National Park officials are searching for a man who went missing over the weekend while backpacking through the park.

Hayden Klemenok was last seen wading into Chilnualna Creek in Yosemite National Park on Sunday.Yosemite National Park

Hayden Klemenok was part of a group backpacking Upper Chilnualna Fall in California on Sunday afternoon when it entered Chilnualna Creek near the trail junction, and has not been seen since. the park said on Facebook and his website on Tuesday.

Park officials ask anyone who has hiked in the Upper Chilnualna Fall area on Sunday or at any other time to contact park dispatch.

“Simply knowing where you went and when you were there can help us focus the search, whether or not you saw someone,” the park said in the post.

Klemenok was last seen wearing a tan brimmed hat, white sunglasses, a red T-shirt, blue swimming trunks and white Adidas sneakers.

An alert on the park’s website Tuesday warns visitors to stay away from rivers and streams due to flooding, noting that they are «surprisingly fast, cold and dangerous.»