This April 14, 2013 photo shows a kayak in the Black Canyon on the Arizona side of the Colorado River. The location is about a mile before the end of a guided trip on the river that begins with a guide company picking you up at a hotel on the Las Vegas Strip first thing in the morning and putting in near the Hoover Dam in a federal security zone that requires escort by an authorized livery service. (AP Photo/Karen Schwartz)) ORG XMIT: NYET913

This April 14, 2013 photo shows kayakers at the Emerald Cave on the Arizona side of the Colorado River. The cave is one of the highlights of a trip on the river that begins with a guide company picking you up at a hotel on the Las Vegas Strip first thing in the morning, putting in near the Hoover Dam in a federal security zone that requires escort by an authorized livery service, and paddling through the Black Canyon. (AP Photo/Karen Schwartz) ORG XMIT: NYET912

This April 13, 2013 photo shows the put-in area at the base of the Hoover Dam, outside of Boulder City, Nev.,for trips on the Colorado River by kayak, canoe and raft. The dam’s power plant is located in a restricted security zone, but so anyone looking to paddle there must be escorted by government-authorized livery services or outfitters. Some of the guide companies will pick you up at your hotel on the Las Vegas Strip some 30 miles away first thing in the morning and have you in the water before lunch. (AP Photo/Karen Schwartz) ORG XMIT: NYET908

This April 14, 2014 photo shows a kayaker with boats on the shore of the Colorado River in Nevada. Outfitters can pick you up at a hotel in Las Vegas first thing in the morning and have you paddling the river through the Black Canyon some 30 miles from Las Vegas before lunch. The put-in area is near the Hoover Dam, a federal security zone, so watercraft must be transported by an authorized livery service, whether you bring your own gear, rent boats or sign up for a guided trip. (AP Photo/Karen Schwartz) ORG XMIT: NYET907