English: Map of battlefield core and study areas.

The 1993 Study Area boundaries did not include the October 23rd action at Byram’s Ford. The CWSAC incorrectly included that action as part of the Byram's Ford battlefield (MO026). The ABPP therefore removed that action from MO026 and incorporated it into Westport (MO027).

The ABPP made extensive revisions to the 1993 Study Area. The Study Area now reflects the following: 1) the Federal approach route from the east; 2) the action at Byram's Ford on October 23rd; 3) troop movements to the east; 4) fighting to the west along and over the Missouri-Kansas state line; 5) the movement of Price's wagon train to the south from the Byram's Ford area; 6) retreats and advances over open ground toward the Confederate wagon train; 7) skirmishing toward, and the action at, Mockbee Farm; 8) the Confederate route to and across Russell's Ford; 8) the skirmish south of Russell's Ford along the Confederate route of withdrawal; and 9) the Confederate route of withdrawal to the south (the boundary extends only as far as the ABPP was able to identify the course of the historic road to Little Santa Fe).

The ABPP expanded the 1993 Core Area to represent the following areas of engagement: 1) fighting at Byram’s Ford on October 23rd; 2) fighting north and south along Brush Creek; fighting to and along the Missouri-Kansas state line; 3) heavy fighting as the Confederate forces began to fall back from Westport (unwittingly) toward Pleasonton’s division; and 4) Shelby's last defensive position along a series of stone walls running east-west.

In addition, the ABPP established two new Core Areas. The central Core Area represents the location of the Union attack near the Confederate wagon train and the running battle across the landscape to Mockbee Farm (this action is not to be confused with the Mockbee Farm action on October 22nd). The southern Core Area represents the Federal assault on the Confederate wagon train (which was repulsed).