Simon Pure was the first Marshal on Mars. His deputy, Rusty, was an android. It's unknown exactly when he began the marshal job, but it probably wasn't long before the events of A Comet's Tale as those events happened over 76 years previously and Pure is still alive in early Sparks Nevada, Marshal on Mars canon. Other events mentioned suggest that humans had not long been settled on Mars, such as that the previous night in town, the humans were voting on what to call Martians. (They settled on Marsites, despit Pure being partial to Marzos.)
In A Comet's Tale, Pure had become tied to some space-train tracks before being rescued by Rusty. They went off to find some UltraCows that were being rustled by The Binary Kid when The Halley’s Comet Gang arrived to destroy Mars. When the destruction began, they hunted down The Binary Kid and his gang, but found they had already been killed.
As the Halley's Comet Gang neared and the destruction ran rampant, Rusty threw Simon into a nearby bunker built by the martians and sacrificed himself to keep Simon safe. This action made Simon realize that Rusty was his best friend, and would continue to miss him into his old age.
Pure was something of an android racist before this happened.
76 years later, before the second appearance of the Halley's Comet Gang, Pure sought out Sparks Nevada and Croach the Tracker to tell his story, and attempt to warn the peoples of Mars to evacuate the planet. Unfortunately, he did little but cause a panic, as Mars was without evacuation plans or escape pods.
- A Comet's Tale (TAH #11)