Le Plessier-Rozainvillers

Contoire (French pronunciation: [kɔ̃twaʁ]) is a former commune in the Somme department in Hauts-de-France in northern France. On 1 January 2019, it was merged into the new commune Trois-Rivières.

Mézières-en-Santerre (French pronunciation: [mezjɛʁ ɑ̃ sɑ̃tɛʁ], literally Mézières in Santerre; Picard: Mézière-in-Santérre) is a commune in the Somme department in Hauts-de-France in northern France.

La Neuville-Sire-Bernard is a commune in the Somme department in Hauts-de-France in northern France.

Trois-Rivières (French pronunciation: [tʁwɑ ʁivjɛʁ] ; literally 'Three Rivers') is a commune in the Somme department in Hauts-de-France in northern France. It was established on 1 January 2019 by merger of the former communes of Pierrepont-sur-Avre (the seat), Contoire and Hargicourt. Hargicourt—Pierrepont station has rail connections to Amiens and Compiègne.

Pierrepont-sur-Avre (French pronunciation: [pjɛʁpɔ̃ syʁ avʁ], literally Pierrepont on Avre) is a former commune in the Somme department in Hauts-de-France in northern France. On 1 January 2019, it was merged into the new commune Trois-Rivières.

Fresnoy-en-Chaussée (French pronunciation: [fʁɛnwa ɑ̃ ʃose]) is a commune in the Somme department in Hauts-de-France in northern France.

Villers-aux-Érables is a commune in the Somme department in Hauts-de-France in northern France.

Hargicourt—Pierrepont station (French: Gare de Hargicourt—Pierrepont) is a railway station located in the commune of Trois-Rivières, near the villages Hargicourt and Pierrepont-sur-Avre, in the Somme department, France. The station is served by TER Hauts-de-France trains (Amiens-Compiègne line).

Hargicourt (French pronunciation: [aʁʒikuʁ]) is a former commune in the Somme department in Hauts-de-France in northern France. On 1 January 2019, it was merged into the new commune Trois-Rivières.

Braches (French pronunciation: [bʁaʃ]) is a commune in the Somme department in Hauts-de-France in northern France.

Boussicourt (French pronunciation: [busikuʁ]; Picard: Bouchicourt) is a commune in the Somme department in Hauts-de-France in northern France.

Beaucourt-en-Santerre (French pronunciation: [bokuʁ ɑ̃ sɑ̃tɛʁ], literally Beaucourt in Santerre) is a commune in the Somme department in Hauts-de-France in northern France.