ELLENSBURG, Wash. — An Ellensburg man remains missing after friends reported that he disappeared while swimming in the Yakima River over the weekend.

Kittitas County sheriff’s deputies say they are continuing to search for 43-year Aaron Harrison, who is believed to have drowned midway between Yakima and Ellensburg on Saturday afternoon.

The sheriff’s office marine unit has been searching for him since then, using a personal watercraft, two boats and ground teams.

A witness reported that Harrison might have been struggling as he went out of sight around the island where the group was swimming, according to a news release issued by the sheriff’s office Monday morning.

Undersheriff Clayton Myers said deputies would investigate all avenues in Harrison’s disappearance because nobody witnessed him go underwater.

Harrison is described as 5 feet, 10 inches tall and 220 pounds. He is muscular and has blond hair, worn in a ponytail. He was last seen wearing black swimming trunks with a white stripe.

Anyone who has seen Harrison or has information about the case is asked to call the sheriff’s office at 509-925-8534.