Calling all climbers. An extreme test of legs and lungs is coming to Colorado.

Organizers from three of the more prestigious cycling races in the state have formed an alliance to launch the Colorado Summit Cycling Series, billed as the country’s ultimate uphill challenge. And it would be difficult to argue with that claim, as the races feature a combined 14,000 feet of elevation gain and finishes atop a pair of iconic fourteeners.

The summer series includes the historic Bob Cook Memorial Mount Evans Hill Climb, The Broadmoor Pikes Peak Cycling Hill Climb and the Westbound & Down/Suerte Guanella Pass Hill Climb.

“For a long time, Mount Evans has been recognized as one of the top uphill races in the United States, if not the world,” said Jennifer Barbour, CEO of Team Evergreen Cycling, owner of the Mount Evans Hill Climb. “This new partnership will provide an extended opportunity to create the definitive Colorado experience for those cyclists seeking a great challenge.”

Registration for the series, which takes place on paved roads closed to traffic, opened Thursday at coloradosummitseries.com. The cost is $219 for adult USA Cycling-licensed riders and $99 for junior levels. The Gran Fondo portion of the event, designed for non-racers, is $285.

Kicking things off June 3 will be the seventh edition of the Guanella Pass Hill Climb in Georgetown. The course boasts grades of up to 12 percent and a peak elevation of 11,670 feet at the base of Mount Bierstadt.

The Mount Evans Hill Climb is set for July 21, when more than 1,000 cyclists are expected to be in Idaho Springs for the 53rd year of the event. The layout measures more than 26 miles and includes 6,000-plus feet of elevation gain. A decent chunk of the race comes above treeline, with a finish at 14,130 feet.

A trek up America’s Mountain serves as the last leg of the series Aug. 11. The route to 14,115 feet is steep and unrelenting, with almost 5,000 feet of elevation gain required over 12 miles. This will be the ninth year of the event.

“We look forward to playing host to the conclusion of this three-part series, which will certainly draw cyclists near and far to be part of this extreme challenge,” said Doug Martin, COO of Colorado Springs Sports Corp., owner of the Pikes Peak Hill Climb. “Pikes Peak, with its steep switchbacks, is a fitting climb to finish the epic journey for participants.”

An overall leader’s jersey will be presented to the top male and female after each race. All finishers will receive a commemorative jersey.