On Saturday, Martin Balding will run his 35th consecutive marathon at Oregon's Crater Lake. Since his first race there in 1979, Balding each year has made the four-plus hour drive from his home near Susanville in northeast California to run one of the toughest marathons in the United States.

Why, at age 76, is he running it again? "Well, I had a lobotomy," he says, laughing.

Yet the truth is, Balding -- who has won the race three times, including in 1994 at the age of 57 -- has come to love the race for its difficulty, its spectacular views, the people who put it on, and the runners it attracts. It's a low-key race in a high-altitude setting, with entrants making long climbs or descents around the edge of a dormant volcano that holds the nation's deepest lake.

The course elevation varies from 5,980 to 7,850 feet above sea level, while August temperatures often reach the 80s or 90s. It's not a race recommended for anyone who might want to set a personal record.

"Oh no, absolutely not," says Rob Coffman, one of three race co-directors. "The winner is … Well, usually if somebody runs under three hours in the marathon, they've accomplished something. That's huge."

Last year's winning time was 2:54:04. In 2010, it was 3:12:12. The women's course record is 3:15:01, or nearly 39 minutes off the record for the Portland Marathon. The men's course record is 2:38.34, set by Bekele Tesfaye of Ethiopia in 1997. Three years earlier, Tesfaye had run a personal-best 2:12:24 at the London Marathon.

"This is the toughest marathon course I've run," Tesfaye told a reporter after winning at Crater Lake. "The altitude makes it hard to breathe. When it's hard to breathe, it makes it harder to control yourself."

Yet each year, runners such as Balding return, and first-timers come from across the nation and around the globe to run. It may be a beast, but it's also a beauty. The race is in a pristine national park setting, and runners catch views of the cobalt-blue water of the lake, pine-covered Wizard Island, the jagged rim of the caldera, and the peaks and valleys beyond the park.

Approximately 7,500 years after ancient Mount Mazama blew its top, what remains is gorgeous. Though the course has changed a bit and the field expanded since Bob Freirich put on the first marathon in 1976, the scenery remains the same, and it remains the race's biggest draw.

"After we had our first run, everybody got excited about it," recalls Freirich, of nearby Klamath Falls, whose 37-year tenure as race director ended in 2012. "Everybody was, 'What a beautiful run.' We had hills we had to climb, but you have this beautiful setting. The visual part of it, looking at Crater Lake, was awesome, and sometimes over 1,000 feet straight down."

And we decided, 'Well, let's keep it going."

Some people will argue that the Crater Lake marathon is the most beautiful in the country. Klamath Falls Herald and News

Over the years, the marathon -- one of four parts to the annual Crater Lake Rim Runs (with a 6.7-mile run, a 6.7-mile walk and a 13-mile run) -- has shown up on various lists of toughest or most-scenic marathons in the U.S. In 1998, Marathon & Beyond magazine ranked Crater Lake as the 21st-best marathon in the country because of its combination of scenery and difficulty.

One judge said it had "the most beautiful scenery of any marathon in North America." Said another: "It is one of the most beautiful areas in which a marathon is held. Period."

In its 2011 ranking of most scenic marathons in the world, Men's Fit Club, a website geared toward men's fitness, put Crater Lake in its top 10, calling it "more than a race; it is an experience of a lifetime."

In March, The Weather Channel -- which tapped into the opinions of several national running journalists and marathoners -- ranked Crater Lake No. 10 on its list of the world's 15 toughest marathons. Freirich, a high school cross country coach, didn't set out to start one of America's toughest races back in 1976.

At the time, he and his running club from Klamath Falls, the Linkville Lopers, decided to drive up to the lake and put on some runs (6.5, 13 and 26.2 miles) because they "thought it would be a good place to have a workout." Fewer than 40 runners participated in what Freirich calls "just a club thing."

The next year, 206 runners participated. By 1978, there were 457 runners. By 1981, it was up to 538 -- 38 more than what is now allowed for the annual rim runs. Marathon participation is usually at 100 or a little more, with sign-ups on a first-come, first-served basis.

It's not the highest-altitude marathon in the U.S. -- the Mount Lemmon Marathon in Arizona, the Pikes Peak Marathon in Colorado and the Madison Marathon in Montana, for instance, all surpass Crater Lake -- but its altitude and route rank it among the most challenging and make it attractive to certain runners. Runners from every state in the U.S., as well as Europe, Asia and Africa have made the trek to central Oregon to test themselves while also visiting one of the nation's most recognizable national parks.

"People come back," says Coffman, a high school cross country coach in Klamath Falls who, with his dad, Ken, and Marvin Dykstra, has taken over the race management from Freirich this year. "And it's not like you're going to break a PR or something like that, it's more for the experience of being at Crater Lake.

"A lot of the people that go to the rockin' race marathons or whatever they are in the big cities, if they like those, they would probably have a hard time. It's a lot of just old, real, back-to-nature stuff [here]. Not music or anything, the big party atmosphere."

Because the race numbers are limited and the route is mostly through areas without structures or spectators, runners often run alone. Coffman recalls that when he ran the marathon a few years ago with a friend, "we were out there, two or three miles at a time, without passing or really much seeing anybody." Its distance from big cities, its small field and its tough conditions mean you'll rarely see the world's best at Crater Lake.

"Most marathoners who are interested in running fast times, you don't go there," Freirich says. And if they did? "Your opponents would say, 'Oh, you had a crappy run, huh?' " he says, chuckling.

The marathon starts on the rim road at Watchman Peak, overlooking Wizard Island. While temperatures may reach the 90s later in the day, often the thermometer is only in the 30s for the early-morning start, when runners wear gloves, hats and fleece jackets that they peel off as the sun rises over the Cascades.

Runners head clockwise around more than half of the rim road (which is 36 miles) before heading down below the outside of the mountain to the finish at Lost Creek campground. Along those 26.2 miles, the topography offers some challenges:

• The race starts with a bit of an uphill grade, that is followed by about a mile or more downhill, says Freirich. "It looks great," he says. "And if you're not looking straight ahead of you, you don't see the fact that, oh my God, you've got about a mile and a half uphill, big time. That gets your attention."

• From about Mile 9 to Mile 15, the uphill grade is constant. "It's brutal," Coffman says.

• At about Mile 18 or 19, says Coffman, the route leaves the rim road and heads down toward the finish -- which may be the toughest part of the whole race. Balding refers to it as the "O. Henry finish," in homage to the American writer famous for his surprise endings. At 22 miles, runners can see the finish line, but are then directed up a dirt road, where they run 2 miles up a steep grade, then turn around. Balding laughs, saying it "adds character" to the race, but not everybody is laughing at that point.

Coffman says that when he and his buddy did the race, their goal was to finish under 4 hours, and as they passed Mile 22, they still had 42 minutes to spare.

"It was like, 'No problem,' we'll make it in 4 miles," Coffman recalls. But it took them about 22 minutes to get up the hill and about 18 to come down. That hill, he says, is "what kicked my butt." Coffman's time: 3:58.

That's 39 minutes slower than his marathon PR, set in Utah. Balding, who has run 65 marathons -- including five Bostons -- has a best of 2:53 at Crater Lake, seven minutes slower than his personal best, set in Nevada when he was in his 40s. The last time he broke three hours at Crater Lake was when he was 51.

"When I was finishing in less than three hours I was thinking, 'Boy, I'd hate to be on that course for four hours,' " he says. "Now it's going on five hours."

Last year, he finished in 4:43, but he was first in his age group. He also holds the age group records for over 50, 60, 70 and 75. He says his favorite part of the race now is crossing the finish line, but what really draws him is the discipline it requires. It makes him feel good to continue training and running. Plus, there's the beauty.

"If I wasn't so driven to finish as well as I could, I'd enjoy the view more," he says, laughing. "It sincerely is beautiful, especially when the weather is clear and cool and conditions are good. But we've had all conditions over 35 years. I haven't actually run in a snowstorm there, but I've started out when it was below freezing and have run while it was misting and raining, too."

This year will be the first time that Freirich won't be in charge of the rim runs. But, he's still going. He wouldn't miss it. He wants to see what's next. And, from almost any spot on the course, the view is something special. That's worth the drive by itself.

"Obviously, the lake sits there all the time," he says. "Sometimes you pull away from it a little bit, where [the route] cuts through the mountain you'll miss it, but either left or right, if you're not looking at the lake straight down you're looking over the mountain country, snowcapped mountains.

"It's a really beautiful run if you can stop to enjoy it a little bit."