BOISE, Idaho (KTVB) -- After four days of intense searching, there's still no sign of missing hiker Luke Richardson. The 25-year-old who works in Hailey was last seen Saturday morning at the Summit Creek Trailhead.

He was reported missing on Monday when he didn't show up for work. "We're focused on finding him," said Blaine County Sheriff Gene Ramsey after search efforts wrapped up Thursday evening. He still has hope the experienced backcountry hiker and climber is alive. Richardson's family is hopeful, too. Aunt Mary Lou Richardson, who lives in Vermont, spoke with KTVB over the phone.

Mary Lou says Luke's parents flew to Idaho to be close to the search effort. They're staying in Blaine County, waiting for any updates on their son. On Thursday, crews searched some drainages off Devil's Bedstead and into the backcountry. Sheriff Ramsey says once again, weather was a challenge. Searchers were brought in earlier than usual because of the dangerous conditions.

Ramsey says it's possible Luke is hurt and waiting for help. Luke's family believes he is injured, and they're praying he's found soon. The Blaine County Sheriff says his office is still following up on leads as the search for Luke Richardson continues.