They were holding onto a boat heading to a Columbia River beach. The 2 swimmers are missing

Two boaters are presumed drowned in the Columbia River after a weekend swimming incident.

The search began Saturday night and continued into Sunday after the two adults slipped off a boat, said the Umatilla County Sheriff’s Office.

Crews were back out searching Monday.

The missing swimmers are Janice Arsenault, 44, of Umatilla, and Trenton Williams, 20, from Idaho, said sheriff’s officials.

They were riding on the dive step of the boat while Richard Kirkendall, 41, of Hermiston, was driving the boat to the area called “Bobby’s Beach.”

When he got to shore, they were no longer there, said the sheriff’s office. It’s not clear if they were wearing life jackets.

Umatilla emergency crews were called just after 7:30 p.m. Saturday.

The beach is along Highway 730, near Hat Rock State Park.

Benton and Franklin county both sent their patrol boats to help with the search late into the night and again on Sunday morning.

Several agencies searched the shoreline and the water.

Columbia Basin Dive Rescue from the Tri-Cities provided a scanning sonar device to help with searching the bottom of the river, said a new release. When the sonar spots something promising, divers will get in the water and check the area, said Scott Ruppelius, dive rescue’s spokesman.

Airplanes also are being used to check the shallow shorelines where boats can’t reach.

Search teams are finding the river murky and difficult to see.

Other agencies that have helped with the search are the Morrow County Sheriff’s Office, Army Corp of Engineers, Umatilla Fire Department, Umatilla County Fire District, Franklin County fire and Lifeflight Air Ambulance.

This story was originally published June 17, 2019 at 10:13 AM.