"We've had a couple of supposed sightings, but they didn't pan out; they were different people," Laursen said Thursday. "Otherwise, we've had no new leads and no one has spotted the Yukon at all that we know of."
Anyone with information about the fugitives is encouraged to call 911.
Law officers also were on alert throughout northern Utah and neighboring states. Both men have family in the Logan and Ogden areas.
Uintah County is heading up the search, but the Department of Corrections is offering support through Adult Probation & Parole, Division of Institutional Operations, Inmate Placement Program, SWAT and investigations, DOC spokesman Steven Gehrke said Thursday.
Laursen said he believes the two are long gone from his county.
"We don't think they're still here, but we're still looking everywhere we can think of in the county," he said Wednesday.
Derrick is serving a sentence for second-degree felony burglary, third-degree felony theft, third-degree felony possession and/or use of a controlled substance, third-degree felony failure to stop or respond at the command of police, and class A misdemeanor child abuse, according to Gehrke.
Braham was behind bars for second-degree felony burglary, second-degree felony theft, third-degree felony theft, third-degree felony burglary and class B misdemeanor theft, Gehrke added.
Laursen said the escape is believed to have taken place at 1 a.m. while the two inmates ostensibly were working in the laundry.
"They had been planning it for a while, since they had to find a way to get behind our two big industrial dryers and then into the vents," Laursen said.
Gaining exit from the area was not simply a case of kicking out a vent, as initially reported, however.
The vents, with 3-by-2-foot openings, had security screening in addition to a vent screen. "It took them a little work to get through those. We didn't think anyone could," Laursen said.
The inmates also had to first defeat a security door and avoid notice of monitors covering the laundry room and adjacent, restricted space where supplies are stored. How they managed that, with six jail staffers on duty at the time, was under investigation, Laursen said.
"Right now, we just don't have that answer," he added. "We still don't know what the heck happened there, and we continue to look into that."
The two were not reported missing until a 2 a.m. jail head count turned up two short.
Meantime, work was under way to better secure the laundry area and the venting. "There have been some major design changes that we're making with stronger screens and grills. Essentially, it's 'Don't even try pulling them off with a tank because you'll just pull the wall down with them.' "
Once through the vent, the inmates fled through the jail's parking lot and, half a mile away, found the Yukon its keys in the ignition and with a full tank of gas parked at a Vernal home.
That, too, was being investigated, though it appeared initially to have been an oversight by the vehicle's driver.
The escapes Wednesday were reminiscent of another jail break by state prisoners from a rural county jail. In 2007, on a Sunday afternoon, convicted murderers Danny Gallegos and Juan Diaz-Arevalo went over the fence at the Daggett County jail. The pair were recaptured six days later near Rock Springs, Wyo.
Laursen said Uintah County Jail has 150 inmates on its roster, 29 of them including the escapees who are being housed for the state prison system.
Laursen said police in Wyoming, as well as Colorado, Idaho and Nevada, also were on the lookout for Derrick and Braham. However, unlike Gallegos and Diaz-Arevalo, neither of Uintah County's escapees has a violent background, Laursen said.
Anyone seeing the escapees, or anyone with information related to the two, is asked to call 911 immediately. Callers also may contactLaursen at 435-621-6092, or by email at firstname.lastname@example.org.