One of Colorado’s most iconic trails is growing.  A nearly 2-mile stretch of singletrack is expected to be built this summer along the Monarch Crest, along a vaunted, well-traveled corridor above 11,000 feet that is part of the Colorado Trail.  “The Colorado Trail is one the greatest trails in the world, and it’s going to be even better now,” said Jon Terbush, executive director of local advocacy group Salida Mountain Trails. Better too, he said, would be the mountain bike ride that is regarded as one of the best anywhere.  The 35-mile Monarch Crest is defined by “world-renowned, high-alpine singletrack,” Terbush said. “This should be continuing that experience and continuing that more remote, backcountry-type experience.”  The experience has not been quite that along a double-track road where mountain bikers, dirt bikers, thru-hikers and equestrians have converged with ATVs and Jeeps. From the top of Monarch Crest off U.S.…