The search continued Wednesday for two Santa Barbara men who have been missing since Sunday in the desert area near the border of San Bernardino and Kern counties.

Chris Rice, 29, and Daniel Carbonaro, 27, left the Cottage Inn Motel in Randsburg on an all-terrain vehicle about 2:30 a.m. Sunday. The outdoor enthusiasts were headed to Cuddeback Lake in San Bernardino County and never returned, according to Kern County Sheriff’s Office spokesman Ray Pruitt.

The Kern County Desert Search and Rescue Team, the Indian Wells Mine Rescue Team and San Bernardino County Sheriff’s Office have been conducting ground and aerial searches since Sunday, “and are continuing the search but haven’t been able to locate them or their vehicle,” Pruitt said. “It’s primarily open desert out there about two hours east of Bakersfield, and there’s a high concentration of abandoned mine shafts.”

Rice, a marketing and promotion manager for Deckers Outdoor Corp., is about 6 feet tall and weighs 185 pounds. He has blond wavy hair and blue eyes, and was last seen wearing a gray sweatshirt and blue jeans. Carbonaro is 6 feet 2 inches tall and weighs about 185 pounds. He has black hair and hazel eyes and was last seen wearing a black FOX windbreaker and dark jeans. They were riding a 2011 white Polaris RZR ATV equipped with ITP tires.

“Dan is a very fit and healthy person,” said Terry Baxter, a friend of Carbonaro. “He is very active and very smart, so all of us believe that he is a survivor. It was a night ride so we hope he was dressed warm enough.”

Authorities said the terrain is rough and that there are numerous open mine shafts in the area — about 15,000 in San Bernardino and Riverside counties alone. Pruitt said the men didn’t take any food, water or cell phones with them.

The state has been either plugging the holes with dirt, covering them with polyurethane foam or fencing them off since the Abandoned Mine Lands Unit was created in 1997.

Mojave resident Wayne Nosala volunteers for Off-Highway Motor Vehicles Recreation. He said the area is a hub for that type of activity and gets extremely busy during the holidays.

“They have been missing for so long that it makes me believe they are incapacitated somehow,” Nosala said. “If I were to guess, they either wandered into a wilderness area and ran out of gas or they could’ve ran into trouble in the mine shaft area.”

The Santa Barbara County Sheriff’s Search & Rescue team and Rice’s and Carbonaro’s friends have joined the search efforts, totaling 180 searchers who are scouring about 1,100 square miles, authorities said.

Although the San Bernardino Search and Rescue team is expected to arrive Thursday, friends are asking for more help.

For more information, click here to connect with the Facebook page about the search, or call Kern County Sheriff’s Office at 661.861.3110 or send anonymous text tips to 847411.

The California Department of Conservation provides these warnings:

» Vertical shafts can be shallow to hundreds of feet deep. At the surface, they may be unprotected, hidden by vegetation or covered by rotting boards. Waste rock piles may look like a fun place to jump over with a bike or ATV, but open shafts may lie on the other side.

» Unstable rock and rotting timbers may present falling hazards.

» Abandoned mines are often used as habitat by wildlife, including rattlesnakes.

“This incident is the worst recipe you could have happen,” Nosala said. “You don’t leave a town at 2 a.m. to go play, leave your cell phones in the truck and go by yourself. The biggest thing is you have to have a travel partner, a second Polaris.”

The Dan Carbonaro and Chris Rice Search Fund has been opened at Santa Barbara Bank & Trust. The account number is 0102413861. Stop by any branch or mail to SBBT/Cottage Office, 220 Nogales St., Santa Barbara CA 93105. Put a note in the envelope with C/O Jonathan J. Katz-Moses: Dan Carbonaro and Chris Rice Search Fund.

All donations will help Rice’s and Carbonaro’s families pay for hotels, supplies, etc. The remaining funds will go toward medical bills if they are found. Call 805.448.8234 for more information.

Noozhawk staff writer Alex Kacik can be reached at Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.