OAKLAND, Calif. -- A plane crashed Saturday afternoon but was in such a remote location in the Oakland hills that it took emergency crews until Sunday morning to find it.

Investigators say the single engine aircraft went down in a canopy of trees 30-50 feet off the ground, but wasn't even visible from the sky. The search began just after 2 p.m. Saturday afternoon near Redwood Regional Park and finally ended Sunday morning.

“What we did was set up an incident command post, conducted a search and found the plane at 10:22 a.m.,” said Paul Catino, spokesperson for the East Bay Regional Park District.

The FAA says the experimental aircraft had engine problems after leaving the Oakland Airport and crashed in the hills 9 miles away.

Officials still don't know how the pilot, Tierry Thys of Oakland, got out but say he was seriously injured before he found help.

“He did walk out on his own and get help on the roadway and was taken from there to the hospital,” said Catino.

Tees has been registered as a commercial pilot since 1999. Published reports indicate that the retired businessman is in his 70's and made news back in 2001 when he flew halfway around the world in a Russian helicopter.

At last report, Tees was at Eden Medical Center with serious injuries .The FAA says it is investigating the matter and won’t expect results for weeks.