After two years of testing the waters in their Amgen Tour of California, race owner Anschutz Entertainment Group and race organizer Medalist Sports are ratcheting up the difficulties for the third edition next February. Until now the highest climb on the course was the 2155-foot San Marcos Pass into Santa Barbara in 2006, while the ruggedly steep Sierra Road, prior to the stage 3 finish in San José, tops out at 1943 feet. Sierra Road remains for 2008, but prior to tackling this redoubtable ascent, the riders will have already climbed the 4360-foot Mount Hamilton; and on the eight-day race’s final stage, they’ll go even higher, when the course takes them to 4906 feet elevation at Mill Creek Summit in Angeles Forest above the finish in Pasadena, 1,078km (or 670 miles) from the start in Palo Alto.

The new climbs will undoubtedly change the dynamics of a race that has already achieved acclaim from the UCI ProTour teams that should again make up half of the starting roster. Defending champion Levi Leipheimer has changed teams, but when he debuts his Astana colors next February 17-24 he should again have the strong support needed to help him achieve a second overall success.

Leipheimer has started each of the first Tours of California by winning the prologue, which finished atop Telegraph Hill after a stiff climb on San Francisco streets, but he’s unlikely to take the 2008 prologue. For one thing it has been moved 50km down the Peninsula to Palo Alto, where a completely flat 3.5km course awaits the starters at the Stanford University campus. A short, fast TT is not particularly Leipheimer’s specialty, but remember that in June this year the California resident was second in the flat 4.2km prologue at the Dauphiné Libéré, only one second behind stage winner Brad Wiggins.

Should Wiggins debut for his new team T-Mobile in California, Britain’s reigning Olympic and world pursuit champion will be favored to take the prologue ahead of his new teammate George Hincapie. Others in contention could be Slipstream-Chipotle recruits Dave Zabriskie and David Millar, along with CSC newcomer Brad McGee.

Stages 1 and 2 of the 2008 race, which was announced Tuesday, are the same as before. Both are again likely to end in mass sprints. The opener to Leipheimer’s hometown of Santa Rosa ended with a nasty crash this year when T-Mobile rookie Gerald Ciolek hit a road stud and caused a domino-like pileup, while the Sacramento stage went easily to CSC’s J.J. Haedo.

On the next day’s stage to San José — where Hincapie and CSC’s Jens Voigt have both triumphed in the past two editions — the group that’s left together at the finish is likely to be much smaller. Leipheimer, who set a remorseless pace on Sierra Road nine months ago, said he would like to go up that demanding climb a second time for him to have a chance of winning the stage. There won’t be two Sierra Roads, but the inclusion of the climb over Mount Hamilton immediately before should be an even bigger bonus for the American.

It’s roughly 80km from Patterson in the Central Valley to the Hamilton summit in the Diablo Range, with a succession of ups and downs, interminable bends on a narrow road that twists through an uninhabited bleak landscape, with more than 5000 feet of actual climbing. Even the 16km descent into San José includes a couple more climbs, while it’s just another 4km on city streets before starting up Sierra Road.

After the rigors of stage 3, the 2008 race follows familiar territory: the longest stage down the Big Sur coast to San Luis Obispo (another field sprint?); the 24km time trial at Solvang (with a slightly different start); and the popular stage 6 from Santa Barbara to Santa Clarita (again including the crowd-infested Balcom Canyon climb). Hincapie performed heroics on that stage in 2007 to help Discovery save the yellow jersey for Leipheimer against a strong challenge by Voigt and CSC, but the twist at the end of next year’s race is yet to come.

After placid circuit races at Redondo Beach and Long Beach in the first two races, the organizers have decided to exploit the mountainous terrain on the Los Angeles skyline (beyond the Hollywood sign). Like the road to Mount Hamilton four days earlier, the ascent to Mill Creek Summit is a series of climbs and dips on twisting roads through wild country. It’s not what you would expect on the final day of a major international stage race.

The sprinters can forget this one. The climbing begins soon after the start in Santa Clarita, with the course lacing through several canyons and over intermediate peaks before summiting at almost 5000 feet. The roads are narrow and relentless and the 28km descent into Pasadena is the prelude to six 8km laps on a reputedly tough circuit around the Rose Bowl.

The outcome could be in doubt until the final turn of the pedals. And that’s what AEG and Medalist are both looking for.