What is the ruling on a wife traveling to visit her imprisoned husband, a distance of 350 km, accompanied by other women without a mahram due to the absence of one for her?

A distance of 350 kilometers is considered travel, and the default ruling is that a woman is not permitted to travel without a mahram unless there is a necessity. Therefore, it is not permissible for this woman to travel to visit her husband merely for a visit unless there is a necessity or an urgent need.