It’s been nine years since Patrick Byrne has been to South Lake Tahoe.

Unlike a typical gambling or camping trip, on this visit Byrne is just passing through. His schedule is tight. He needs to travel 4,000 miles on his bike to meet the Pan-Massachusetts Challenge and raise money for a cause all too familiar to him.

As a three-time survivor of seminoma, a type of cancer that had infiltrated his whole body, Byrne, 37, was approached by the Dana-Farber Cancer Institute to help raise awareness, and to help benefit the Jimmy Fund, which supports cancer research at the institute.

Last year PMC raised $8.5 million. This year the goal was to raise $9 million, but Byrne – a dot-com millionaire – challenged the institute to set the stakes at $11 million, pledging an additional $1 million of his own money if the initial goal is met.

Byrne is the CEO of Overstock.com, a Salt Lake City based company that sells excess inventory of consumer items at large discounts.

“It makes me realize how selfish I’ve been in the past because I wouldn’t talk about my cancer since I didn’t want to be known as the ‘cancer guy,’ ” said Byrne, whose cancer has been in remission for 12 years. “PMC pointed out to me that I wasn’t expected to survive, but I did. That’s why I’m doing this ride. I like showing people that you can survive and that a good part has to do with your spirit.”

Having been cancer-free for 12 years, Byrne is no stranger to the white line on the road. Each time he won his bout with cancer he rode solo across the country. This three-time successful feat caught the attention of PMC who approached him to ride for others. This is the first time, however, he has started from San Francisco and has gone up and over the Sierra Nevada, through the Nevada basin, over the Rockies and into the eastern region.

“Each time I do it I swear I’ll never do it again,” Byrne laughed. “At least not in the next 10 years.”

Although just completing the first leg of his trip, Byrne has already had an exciting time on his way to Lake Tahoe.

En route on U.S. Highway 50 near Placerville, Byrne was pulled over by a California Highway Patrol officer telling him he could not ride his bike on the road. Even though it is legal to ride a bicycle on a state highway, the officer would not allow it and even threatened to haul Byrne to jail. Either that or he would have to hop the guardrail and carry his bike to the top.

After opting for the second choice, Byrne carried his bike for three hours until he ran into another CHP officer who told him it was OK for him to ride on the road.

According to Sgt. Lon Kurtzman, who had not spoken to the officer in question, there are some portions of Highway 50 that have restricted access. Certain sections are also extremely treacherous and unsafe for bicyclists, he added.

Once Byrne pulled into South Lake Tahoe he decided to take a break and have the South Shore Bike and Skate Shop tune his bike up. He said they “did a terrific job.”

The tune-up will no doubt help him complete the miles between here and his destination of Boston, which he hopes to reach by Aug. 4 in time to join 3,100 riders in a group cancer ride to Cape Cod.

Until he joins his fellow bicyclists, Byrne is traveling without a motorcade behind him. Pedaling 10 to 12 hours a day and burning about 10,000 calories, Byrne will cover between 70 and 80 miles a day. He will ride for six days straight before taking a day off. In the interim he will hide his bike in some brush and camp outside overnight and then wake up to be on the road by dawn.

“It’s not so much physically challenging but what make this hard is the mental challenge,” Byrne said. “It can be miserable when it’s raining or when it’s scorching hot. When you’re pedaling, the hours of monotony can be punctuated by moments of terror like when a spoke breaks or a car is just over the crest.”

Since he doesn’t have time for a leisurely meal until he takes a day off, Byrne will munch on beef jerky and fruit. He’s eaten enough Power Bars to last a lifetime, he said.

The food, meager though it may be, has always sustained him in previous rides, and he has never run out. It’s the water, or the lack thereof, that he’s concerned about, so he will take iodine pills to purify any form he happens upon.

On a recumbent bike, it would seem that pedaling uphill would be especially grueling. But for Byrne, he says the western mountains are easier since you can “just put your head down and focus on getting up the hill. With the eastern mountains you end up sprinting up the little hills and then you end up really winded, worse then if you just would have steadily climbed.”

In addition to being an expert rider, Byrne also boxes, wrestles, rock climbs and has a black belt in martial arts.

Byrne’s Web page Overstock.com allows people to make a monetary pledge for his ride by clicking on the “CEO trip” icon.

“I enjoy doing this for a cause rather than doing it for myself,” he said.