According to the CHP a one seat helicopter went down about 200 yards off 101 Northbound, near Embarcadero and Bayside.
At around 4:45 p.m. the Robinson R-22 helicopter experienced engine problems while approaching Palo Alto Airport, which was when the pilot made an emergency landing in a marshy area near Embarcadero Street and Highway 101.
Initial reports say the pilot, who was the only person on board, was not injured.
Palo Alto PD is handling it, even though it is near Redwood City.
The FAA and NTSB will investigate the incident.