SACRAMENTO, Calif. -- Defending champion Levi Leipheimer of Santa Rosa will be among the cyclists taking part in this year's Amgen Tour of California, which begins at Stanford University on Sunday and visits Sacramento on Tuesday.

The third-annual 650-mile tour, which is billed as the best collection of talent to compete in a professional cycling stage race in the United States, will end on Feb. 24 in Pasadena.

Last year, the tour attacted thousands of cycling fans to downtown Sacramento. Riders will roll into Sacramento Tuesday afternoon as they complete a stage that begins earlier in the day in Santa Rosa.

Competitors will ride from Modesto to San Jose on Wednesday.

This year's tour will include 17 teams and 136 riders from 27 countries, including competitors from Slovenia, Australia, New Zealand, Ukraine, Luxembourg, Kazakhstan and South Africa.

"We've never had a group this accomplished in our race and can't wait to see them out on the roads of California," said Andrew Messick, president of AEG Sports, in a prepared statement.

The field will include riders from well-known teams such as Astana, High Road, Quick Step, Saunier Duval-Scott and Team CSC, which returns to defend the title as the overall classification winner of the 2006 and 2007 Amgen Tour of California races.

Some of the notable riders expected to begin the race in Palo Alto on Sunday include:

California Natives/Residents:

Astana: Levi Leipheimer, Santa Rosa

BMC Racing Team: Scott Nydam, Santa Rosa; Antonio Cruz, Long Beach

Jackson Stewart, Los Gatos; Taylor Tolleson, Watsonville

Bissell Pro Cycling: Ben Jacques-Maynes, San Jose; Aaron Olson, Santa Barbara; Scott Zwizanski, Sausalito

Health Net Pro Cycling Team Presented by Maxxis: Roman Kilun, Berkeley

Jelly Belly Cycling Team: Bernard Van Ulden, Belmont

Rock Racing: Fred Rodriguez, San Francisco

Slipstream Chipotle Presented By H30: Steven Cozza, Petaluma

Toyota-United Pro Cycling Team: Cuban rider Ivan Dominguez, Chatsworth

American Race Champions:

Levi Leipheimer, Astana, 2007 Amgen Tour of California

Janez Brajkovic, Astana, 2007 Tour de Georgia

George Hincapie, High Road, 2007 Tour of Missouri

Chris Horner, Astana, 2003 Tour de Georgia

Top 2007 Amgen Tour Of California Notables:

Levi Leipheimer, Astana: Prologue; individual time trial; first overall

Juan Jose Haedo, Team CSC: Stage 2 and 6; first overall in sprint classification

Robert Gesink, Rabobank: First overall Best Young Rider

Danny Pate, Slipstream Chipotle Powered By H30: First overall Most Aggressive Rider

Jens Voigt, Team CSC: Second overall; stage 3

Paolo Bettini, Quick Step: Stage 4

Ivan Dominguez, Toyota-United Pro Cycling Team: Stage 7

Fred Rodriguez, Rock Racing: Tenth overall in sprint classification

Bobby Julich, Team CSC: Fourth overall

Team CSC: Defending team champions (2006 and 2007)

World Champions:

Paolo Bettini, Italy, Quick Step

Tom Boonen, Belarus, Quick Step

Bradley Wiggins, Great Britain, High Road

Fabian Cancellara, Switzerland, Team CSC

Oscar Freire Gomez, Spain, Rabobank

Gerald Ciolek, Germany, High Road

Dmytro Grabovskyy, Ukraine, Quick Step

Olympic Medalists:

Paolo Bettini, Italy, Quick Step

Bobby Julich, United States, Team CSC

Bradley Wiggins, Great Britain, High Road

Bradley McGee, Austria, Team CSC

National Time Trial Champions (By Country):

Vladimir Gusev, Russia, Astana

Edvald Boasson Hagen, Norway, High Road

Fabian Cancellara, Switzerland, Team CSC

Gustav Larsson, Sweden, Team CSC

David Millar, Great Britain, Slipstream Chipotle Presented By H30

David Zabriskie, United States, Slipstream Chipotle Presented By H30

National Road Champions (By Country):

Levi Leipheimer, United States, Astana

Fabian Wegmann, Germany, Gerolsteiner

David Millar, Great Britain, Slipstream Chipotle Presented By H30