The pair had three days worth of water left when they became stranded in a remote area with two flat tires, according to a note they left on their vehicle, the Inyo County Sheriff's Office said.

It's been four days since Alexander Lofgren, 32, and his girlfriend Emily Henkel, 27, failed to return April 4 from a camping trip in challenging terrain.

After two days of searching hotels and back country campsites, authorities located their 2018 white Subaru Forester around noon on April 8. The couple was spotted by a search aircraft on a "very steep ledge" in a "very remote area" of the park, the sheriff said.

"It is unclear at this point what condition Lofgren and Henkel are in," the sheriff's office said in a 4 p.m. update on its Facebook page.

The short note on they left on their dashboard — "Two flat tires, headed to Mormon Point, have three days' worth of water" — helped searchers zero in on the pair, it said.

Rescuers initially attempted a "hoist operation" to reach the couple, but two team members who rappelled down were not able to reach them "due to the extreme location," the sheriff said.

A technical team from Inyo Search and Rescue was enroute to the area and was expected to descend the canyon in a second attempt.

Lofgren, a former Army combat engineer who served in Afghanistan, is a staff member who works on military and veterans issues in the Tucson office of U.S. Rep. Raúl Grijalva. Emily Henkel said she works as a marketing coordinator for the Arizona Army National Guard.

The sheriff's office said Lofgren and Henkel were experienced campers. Lofgren is known for camping in remote areas at undesignated campgrounds and is believed to have had at least a day's worth of food with him, the sheriff said.

Grijalva said he is "optimistic that Alex will be found quickly, and my thoughts are with his family as they await the news."