Teams will resume their search Friday for two who went missing at the Joshua Tree National Park as the search for missing hikers stretches into a second week.



"There's enough track evidence," said George Land, a ranger and spokesman. "We believe they're still in the park."Rachel Nguyen and Joseph Orbeso, recent students at Cal State University Fullerton, were last seen setting out from their airbnb rental for a hike a week ago Thursday, Land said. The property owner cautioned them to bring plenty of water.



When they had not checked out a day later, the property owner notified authorities, and a park ranger located their car in a parking turnout for a trailhead, Land said. The trail, known as the Maze Loop, goes through an area with high rock walls.



Footprints led from the car to the trail, but given the sandy surface, were difficult to follow with certainty for any distance. Checking cellphone provider records, authorities received a "ping" from somewhere in the park late Thursday.



Despite intensive daily searches with police dogs, airplanes, and helicopters, there has been no further evidence of the two.



"I can't remember a search that I've worked on where there wasn't some trace ... discarded water bottles, clothing, Cliff bar wrappers, whatever it is," said Land. "And we just haven't found anything."



Located in high desert hills and rocky slopes north of Palm Springs, Joshua Tree has been subject the past week to extreme weather, including triple-digit temperatures punctuated by thunderstorms, with lightning and heavy downpours.



What kind of supplies and equipment the pair brought with them is not known.



"Our hope is that her 10 years in the Girl Scouts prepared her for an emergency," said Son Nguyen, her uncle.



Members of both families have traveled to Joshua Tree to assist with the search. They described Nguyen and Orbeso as friends, not a couple. Both had previously attended CSUF. Neither is enrolled for this coming fall term, according to the University.



In a park that now receives 2.5 million annual visitors, a handful periodically go missing, and most are quickly found, Land said.



Last November, a Los Angeles couple who disappeared after speaking of traveling to Joshua Tree were found instead 100 miles to the south in the desert near the Mexican border.



In another disappearance last year, authorities suspect the man's car may have been driven into the park and abandoned.



Three decades ago, Joshua Tree became the focus of an intensive search after 3-year-old Laura Bradbury disappeared from the Indian Cove campground area where her family was staying. Authorities suspected she had been abducted. Two years later, skeletal remains of a small skull believed to be of the missing child were located in the park.



Joshua Tree draws from around the world. Thursday a steady stream of visitors, many from Europe, inspected the missing notice posted at the entrance of the visitor center, before proceeding into the park to hike.



"It could be dangerous because of getting lost," said Jan Noeske, on holiday from Cologne, Germany.