 Story highlights Authorities end cattle roundup, return livestock for safety reasons 
 
 Troopers reopen northbound Interstate 15 about 80 miles outside Las Vegas 
 
 "Tensions are still near the boiling point," Sen. Heller says 
 
 Some supporters of rancher were armed, authorities say 
 
 A tense, weeklong showdown appeared to end Saturday between the federal government and supporters of a Nevada cattle rancher battling the Bureau of Land Management (BLM) over grazing rights on federal land. The rancher couldn't be immediately reached for comment Saturday after the feds shut down the roundup. Gov.
– After a confrontation between locals and federal officials this week, the US has ended a Nevada cattle roundup early, CNN reports. "We have made a decision to conclude the cattle gather because of our serious concern about the safety of employees and members of the public," said Neil Kornze, director of the Bureau of Land Management, who was confirmed just this week. Some 400 cattle were gathered in the weeklong roundup; officials had planned to gather 900, the AP reports. Officials prompted local protests when they began gathering cattle that were illegally grazing on federal land some 80 miles northeast of Las Vegas, CNN notes. The animals belonged to rancher Cliven Bundy, who has allowed the illegal grazing for two decades. At issue is a 1993 law that altered grazing rules in order to protect an endangered tortoise. Bundy now owes the government $1 million in grazing fees, officials say. Bundy counters that according to the Constitution, Nevada should be in charge of such fees, rather than the federal government. A videotaped protest on Wednesday resulted in officials saying they were assaulted while protesters said they were thrown on the ground and tasered.