Animal researchers are looking for big horn sheep in the Arkansas River valley between Canon City and Salida.Wildlife officials are catching the animals and putting tracking collars on them."We're going to monitor population size, animal survival and movements in the canyon," said Brian Dreher, senior wildlife biologist.The goal is to monitor the big horn sheep in advance and during the artist Christo's project "Over The River."Christo plans to use a system of anchors, frames and cables to suspend 5.9 miles of fabric across eight spots along a 42-mile stretch of the Arkansas River. The construction is anticipated to begin this year, culminating in a two-week display in August 2014.Christo will be required to put several mitigation measures into place for bighorn sheep, anglers, drivers, boaters and birds.The Bureau of Land Management approved the plan in November. However, in January, students in the Environmental Law Clinic at the University of Denver Sturm College of Law filed a lawsuit to stop the project on behalf of the grassroots, all-volunteer organization Rags Over the Arkansas River.