The search for Luke Bucklin, co-founder and president of Bloomington-based Sierra Bravo Corporation, and three of his sons-Nick (14), Nate (14), and Noah (12)-continued Thursday morning as crews searched a remote area in western Wyoming.

Bucklin and his sons were reported missing Tuesday after the small plane they were traveling in from Wyoming lost contact with ground control at about 3 p.m. Central Standard Time on Monday. Bucklin was piloting the plane, which was headed for Minneapolis.

According to the Fremont County Sheriff's Office in Wyoming, a four-member search team continued to search for the plane before first light Thursday. The team, which has been searching since Tuesday, was joined by a second ground team that headed for a nine-square-mile search area east of Gannett Peak early this morning. As of 11:30 a.m. on Thursday, search teams had still not found the plane.

“Our ground teams will be looking for clues and our air teams will be looking for the aircraft,” Incident Commander Chip Williams said at a Thursday morning briefing. “This is a huge search area and we will be acting on intelligence as the day goes on. We're going to hit this hard again today.”

In addition, a fixed-wing aircraft will join the search. The aircraft is equipped with highly sensitive detection equipment that may be able to locate automated emergency transmissions from the plane, which have not yet been detected to this point.

The sheriff's office said that challenges are arising due to the remoteness of the site. In particular, search helicopters and ground crews working in the drainages east of Wyoming's highest peak have to relay information via satellite telephones or from aircraft flying above the ridge lines.

The sheriff's office also reported that a fast moving winter storm front hit the search area with up to 15 inches of snow Tuesday night, which made observation from the air difficult.

On Thursday, there was increasing cloudiness, windy conditions, and slightly warmer temperatures, according to the sheriff's office.

Bucklin was retuning home from a Wyoming vacation and had been flying the plane, a four-seat single-engine Mooney 201, for about an hour when radar contact was lost. Bucklin's three other children-Sarah (19), Samantha (16), and Oliver (5)-were not on the plane.

Bucklin's wife and the boy's stepmother, Ginger Bucklin, has been posting regular updates on the family's blog.

“We are getting wonderful support, including meals, prayers, and lots of hugs,” Ginger wrote on the blog. “We welcome your help but right now, our only urgent need is for your prayers.”

Sierra Bravo, which was founded in 2003, has most recently been doing business as Nerdery Interactive Labs. It is among the state's largest Web development and design companies based on its Web revenue, which totaled $8.6 million in 2009. The company employs about 100 people and specializes in Web development, including application programming, user-contributed video content, lead generation microsites, and desktop widgets.