Mark Rodriguez

Constable Mark Rodriguez is an RCMP officer in the town of Hudson, Alberta.

Amy met Mark when she helps him save a child from drowning in the Sheep River. Later when Amy works with his horse to overcome fear of water, she discovers that it is the same river where Mark's brother drowned. He yells and breaks down crying in front of his horse, and this solves the horse problem.

Later he starts dating Lou. Just as Lou starts to get really attached to Mark, she catches him in the city kissing another woman. Lou ends their relationship immediately.

Season 2
When Mark is out for a ride he comes across a boy calling for help from Sheep River he goes to help, Amy arrives and goes to get help. He goes to Heartland to ask Amy's help with his horse Venture who is now scared of water and refuses to let anyone ride him. He tells Amy that he doesn't believe in what she does but he was told to bring Venture here. He gives the impression that he doesn't care about Venture but when he's leaving Amy sees him becoming upset in his truck. When he arrives to check on Venture's progress he starts flirting with Lou. He tries to ride Venture and he refuses to let him saddle him. Mark leaves annoyed at the lack of progress. Amy and Ty take Mark to Sheep River and she talks to him about the trauma of the accident from his brother not the recent accident. He becomes furious and leaves. He goes to pick up Venture and Amy apologises to him but tries to get him to help with one more plan. She wants Mark to try join up but he doesn't believe it will help, Ty goads him into it proving successful. He starts to see flashbacks of his brothers death and breaks down causing Venture to join up. Lou arrives at Heartland when he's heading out and he and Lou have a moment. (Holding Fast) Scott calls the RCMP about the truck load of horses. Mark goes to Heartland and asks out Lou on a date when Scott arrives. Mark tells them that nothing illegal has been done so he can't do anything and the only way to save the horses is to buy them. Mark manages to arrive in time to help the horses as Ed is taking them back. He tells him that one of his employees has told him all about his mistreatment of employees and horses so arrests him. This means all the horses gets to stay at Heartland. He arrives on Friday to pick up Lou for their first date. (Summer's End) Mark is eating with Lou at Maggie's, when they are interrupted by Tim complaining about all his cattle paperwork. Mark tries to get him to see how important having the right paperwork is in order for them to trace stolen cattle. Mark takes Lou out on a date as they see a rancher moving cattle, disappointed by the lack of support by the police. He calls a meeting at Maggie's for all the ranchers, he tries to get them to help each other, since there's not enough man power at the RCMP. He's adamant that no one get in between the rustlers and their cattle but they call the police. A rancher brings in his cow to showcase their point of their lives being wrapped up in their livestock and ends in chaos. (Showdown!) Lou gives mark the new mixed CD she's made him, he tells her it's cute. He then gives the family an update, he tells them that they haven't been able to find the cows or track the vehicles involved. He gets frustrated at Tim and tells him he should have arrested him for getting involved and storms out. Lou tries to calm him down and reminds him of their date tomorrow. He tells her that he forgot he has a meeting. When Lou's in town she sees Mark kissing another girl in his car listening to her mixed CD. She walks away but mark follows her, he doesn't understand why she's upset when they weren't exclusive causing them to break up. (True Enough)

Romantic
Lou

Lou and Mark develop a quick connection. He soon asks her out on a date and she accepts.