Max by Clarissa Lake

Max Steele, a former cyborg marine ranger, returned to Earth with his team to restore law and order to the North American West. He is on his way to Northern California to take over securing order in the San Francisco megalopolis. Although he preferred his rural territory, he knew he wasn’t needed.
Max considered himself socially repressed and was not looking forward to dealing with people in the urban ruins. He even worried he would put off his genetic mate if he ever found her.
Falyn Wayne is running for her life from four men on her horse Argus. Max sees them from the air and decides to intervene, putting himself between the men and the fleeing woman. Sending them on their way, he finds Falyn standing over her downed horse with a pistol sobbing because it has broken its leg, and she needs to end his suffering. Max stops her, but as he approaches, Falyn shoots him…