Authorities resumed their search Sunday morning for a Santa Rosa couple whose Petaluma-bound plane went missing on April 17 after taking off from Truckee.

Two Civil Air Patrol planes took off around 10 a.m. to search for Mark and Brenda Richard’s white-and-blue Socata TB-20 Trinidad, said Maj. Kathy Johnson, spokeswoman for the Civil Air Patrol. A third plane left in the afternoon to assist.

The patrol suspended its search Saturday afternoon because of strong winds above an area of the Sierra Nevada mountain range where the plane had last been tracked by radar and cellphone information.

The Civil Air Patrol, along with the California National Guard, the CHP and local authorities are focusing on a 270-square-mile area located 18 miles northwest of the Truckee-Tahoe Airport, Johnson said.

Fresh snow on the mountain range has made it difficult to spot the aircraft, especially because the plane’s bottom is white, Johnson said.

“Everything is covered in snow,” she said. “They had fresh snow just after they went missing.”

Flight crews have taken more than 8,000 high-resolution images within the past week to try to pinpoint where the aircraft might have landed, Johnson said.

“It takes about five minutes a photo to go through,” she said. “As you can imagine, it’s a huge undertaking.”

You can reach Staff Writer Bill Swindell at 707-521-5223 or bill.swindell@pressdemocrat.com. On Twitter @BillSwindell.