Mark is the program director of the California University news station. While scouting the Beverly Hills Beach Club reunion for Brandon Walsh, Mark meets Kelly Taylor and quickly became infatuated with her.
After convincing Brandon to work at the news station, they hired Tracy Gaylian as the new anchor and immediately had problems when she got stage fright. But, she came through despite a hangover and the partnership of Mark and Brandon was off to a good start. However, when Steve Sanders pulled a prank on the Chancellor, Milton Arnold, by streaking through a speech, Arnold demanded the tape be turned over to him. Mark and Brandon shared differing viewpoints and Mark turned over the tape, which was nothing but static, thanks to a strategically-placed magnet by Tracy.
Later, while throwing a party at the Hollywood Hills house he shared with David Silver, a brush fire threatened to destroy his home and the surrounding area. Despite warnings from the local firemen, Mark decided to stand his ground and save his home. Brandon, Kelly, Tracy Gaylian, Steve, Clare Arnold, and David stayed with him and helped to save the home while Donna Martin saved a deer and was rescued by Cliff Yeager. Afterwards, Mark asked Kelly out on a date and she accepted.
Mark and Kelly dated for a while, most of which involved Mark trying to sleep with Kelly. Things took a turn for the worst when Brandon and Mark applied for the Dryer scholarship, causing tension between them. When Brandon won the scholarship, Mark didn't take it very well. He blew up at Kelly and blamed her for his loss, at which point she dumped him. Following the breakup, Mark was never seen again.
- According to a 2010 interview with writer/producer on Seasons 3–7, Larry Mollin, James was fired for allegedly being anti-semetic, which was never confirmed in any way:
- 'Here’s another story about the old man [Aaron Spelling]: We had to create a new guy for Kelly and we hired a guy, paid him a bunch of money. His name was Dalton James. He played a character called Mark. He ran the TV station. So we’re doing 32 episodes so we’re writing away and we have half the season written but we’ve only shot through episode 5. We get called in to the old man’s office. “We have a big problem.” I go, “What’s the problem?” Well, we knew that Jennie didn’t like him. So it’s me and Steve Wasserman, and he goes “I just found out that Dalton James is anti-Semitic.” We go, “What?! That f*cking–” And he goes, “Well, we have to get rid of him.“ And we go, “Well, we’ve written another 10 episodes for him! We have this whole story!” And he goes, “Well, he’s anti-Semitic. I can’t have him here.” And we go, “You’re right!” and we get all pissed off and then we walk out to the elevator and Steve goes, “He’s a f*cking liar.” [Spelling] knew we were going to complain if it was just that Jennie wanted to get rid of him, so he made up a story that the guy was anti-Semitic so we’d be pissed off and write him out. And that’s the kind of guy [Spelling] was. [...] With him, the ends justified the means and screw the actor’s or anyone else’s reputation. He played at the game hard. We had no evidence that Dalton James was anti-Semetic. Most likely wasn’t.'