The pilot obtained a standard preflight weather briefing with Lockheed Martin Automated Flight Service Station and also Data Transformation Corporation (DTC) direct user access terminal (DUAT) before departure. The estimated flight duration calculated by "DUAT.COM Flight Planner" based on pilot input pertaining to flight performance parameters, and winds aloft forecasts was 2 hours 59 minutes, with an estimated fuel consumption of 29.3 gallons. The trip fuel consumption was based on the pilot's historical experience of 10.0 gallons-per-hour (gph). The pilot stated that the flight departed with 34 gallons usable fuel on-board; the time of departure based on a witness account was 1215. After takeoff, the pilot obtained visual flight rules (VFR) flight following, and proceeded towards the destination airport. At 1522:48, or approximately 3 hours 7 minutes after takeoff, the pilot advised the controller, "mayday uh four two romeo's uh out of fuel." The controller advised the pilot of a nearby airport but the pilot advised she was unable to land there. The pilot stated that she maneuvered the airplane towards a field and during the descent she heard the sound of tree contact then recalls nothing further. Inspection of the accident site and wreckage by a Federal Aviation Administration inspector revealed the left wing was separated. No fuel was found in either main fuel tank, and there was no evidence of leakage from either fuel filler cap or sump drain. A total of 1.5 ounces of fuel were drained from the carburetor bowl. Inspection of the engine revealed no evidence of preimpact failure or malfunction.