The Orne () is a river in Grand Est, north-eastern France, which is a left tributary of the Moselle and sub-tributary of the Rhine. Its source is in the hills northeast of Verdun. It flows east and joins the Moselle near Mondelange, between Metz and Thionville. Name "Orne" may originate from autura (a river, cf. Eure), or onna (a river) as mentioned in Endlicher's glossary of Gallic names De nominibus Gallicis, in which these words are translated into Latin as flumen. If so, then there is no relationship with the name of the Orne river in Normandy, which is referred to as the Olina by Ptolemy, a homonym of Fluvius Olne, the Orne saosnoise in Sarthe, which Xavier Delamarre traces back to the Celtic olīnā (elbow). Geography The Orne is long. It rises at an elevation of in the Côtes de Meuse, in the commune of Ornes. It flows through Étain, Conflans-en-Jarnisy, Auboué, Homécourt, Jœuf, Moyeuvre-Grande, Rosselange, Rombas, Clouange, Vitry-sur-Orne, Gandrange and Richemont, where it joins the Moselle at an elevation of . The people of the Pays Orne-Moselle and Pays de l'Orne communes have formed an association for the creation of a riverside trail named "Fil Bleu" ("Blue Thread") or "Promenade des Berges de l'Orne" ("Promenade of the banks of the Orne"), which will extend the length of the riverbed. Currently the trail extends about between the communes of Rombas/Clouange and Valleroy, and is either concrete or macadamised over all of this length. Between Rombas/Clouange and Rosselange, it exists on both sides of the river. The section of about from Joeuf to the naval base at Homècourt is marked by a number of bridges and footbridges permitting passage from one bank to the other. Two of these footbridges are however no longer passable: the "passerelle de Moyeuvre Grande" (for which a detour via road bridge exists) and the "passerelle de la base nautique d'Homècourt". The trail is frequently used by both pedestrians and cyclists, as well as by those on rollerblades. It crosses the communes of Rombas, Clouange, Rosselange, Moyeuvre Grande, Joeuf, Homècourt, Aubouè, Moineville and Valleroy. Since 2011, the trail has been extended from its prior endpoint to the commune of Amnéville-les-Thermes. Between of it have been built and are being maintained by the municipality of Rombas. Tributaries The Orne's principal tributaries and subtributaries are: The Orne is also fed by water pumped out of the mines at