Its first assignment was a mapping expedition, deep into the Beta Quadrant, that was scheduled as a four month exploratory tour. In Montana’s first week of this tour, they came across the beginnings of a new Star. Montana’s crew were witnesses to its formation, and tagged it as BXNAF-79. Captain Armstrong recommended that Starfleet send a Science Vessel to monitor its continued growth.
By November, half way though the expedition, Montana had also made two first contacts, one with a species called the Omeron, who have holdings over a small region of space, about half a dozen planets, across about the same number of Star Systems. The Omeron were amenable to the idea of holding diplomatic talks with the Federation. The Second Species, the Athon, had just made their first Warp jump when Montana passed through their space. Although the initial shock of the Jupiter-class Starships appearance had overwhelmed them, they were quite accepting of the Federation and Starfleet, Montana’s crew in particular. From Captain Armstrong's Log
"They seem a surprisingly advanced race, considering the only recent invention of Warp Drive. There Medicinal techniques are significantly further along the technological scale than Earth was when Cochrane made his Warp jump".
Montana’s crew reported that the Athon were open to further encounters with the Federation. Beyond that however, Montana spent much of those early month - up to November - just mapping relatively empty space. In late November though, Montana picked up a dense pocket of Planetary systems. They set a course for this region, before locating another promising find, an Asteroid region that seemed to have interesting mining properties. Not long after this, Montana’s Sensors detected some unusual readings that corresponded to spacial distortions that are commonly found amongst wormhole regions.
In order to cover more ground, the Montana headed for the distortions, allowing for Montana’s Sensors to get a full clear picture of what was actually causing such distortions. Captain Armstrong also elected to deploy the Runabouts Angel, and Billings, to investigate the other to locations. The Angel conduction a 10 day tour through the Planetary Cluster, and the Billings conducting preliminary Mining Operations in the Asteroid Field.
The Runabout Angel encountered two new species, one of which resulted in the beginnings of Official First Contacts, and the other was a Pre-Industrial Civilization. They also used the ARGO Rover Vehicle to conduct several small scale planetary survey's on 7 different worlds.
The Billings found naturally occurring deposits of Trilithium in the Asteroids, along with several other properties that initial surveys proved to be promising.
As for Montana herself, when the ship arrived at the co-ordinates of the spacial distortions, rather than a wormhole enriched location, the crew discovered a "Starship Graveyard", per see, hundreds of biologically dead Starships, many centuries old. In an effort to learn about the ships, and the species that spawned them, as well as to learn about what happened to them, Captain Armstrong and the crew conducted several away missions, to investigate.
Whilst Montana was within this "Graveyard", members of the crew began to disappear. Along with members of the crew, even plant and animal life carried aboard Montana began to vanish, seemingly without cause. Things became even more serious when the Bio-neural gel packs began to disappear, causing vital ships systems to fail, including Warp drive, and the Impulse engines. Montana’s crew began to disappear in droves while those remaining worked to figure out what was happening, and to find alternate methods to operate Montana 's other systems.
The cause of these disappearances turned out to be a Cosmozoan based lifeform, existing in subspace, feeding on Biological Matter. Beyond that, the Montana and her crew did little more to investigate the lifeform, as Montana’s systems came back online, and the crew used that opportunity to escape. Montana’s crew complement was reduced from 1,744, to 651. (ST:Mon - "The Graveyard" Parts One and Two)
Montana’s exploration continued, as the round trip bought the Jupiter-class starship back towards Federation Space. En Route, the Montana was attacked, and the Crew taken by a species called the Zantax. Montana itself was towed into Orbit of one of their facilities, repaired, and left abandoned, waiting for the crew to return. The Zantax themselves were merely attempting to learn about Montana 's crew in their own way. (ST:Mon - "And Cut...")
In February of 2383, after a month's break, the Montana was dispatched to the Breen Border, on a resupply mission. It was suspected that the Breen had been making moves to attack Federation Colonies along the Border. However, with the arrival of Montana and her Convoy, reinforcing the region, the Breen Threat seemed to subside. During this time, Montana’s Second Officer was attacked, and near fatally wounded. If it hadn't been for his Klingon Physiology, CommanderQurn wouldn't have survived.
In May of 2385, the Montana left Deep Space 3 on a mapping Expedition into a region of space known as the Hrakert Rift. This Region of space bore properties similar to the Briar Patch, although lacking in the Metaphasic properties found within the Region.
-[As Montana entered the Rift, they detected a Temporal anomaly, and upon further investigation, encountered the USS Montana-C, a Saturn-class Starship, from the early 25th Century. It's Captain, Captain Armstrong's own son, only considerably older than he had been the last time Sandy Armstrong had seen his son Nathan. Both Montana’s were trapped in a Temporal Bubble, Parallel to the normal timeline, until Montana Science Officers found a way to return the Montana-C to its Original Time, and seal the Rift. When this happened, the meeting of the two Montanas was erased from history, and the meeting never happened.](ST:Mon - "Back to the Future")
Much of the Exploration, proved to be fruitless, however, as there was little to discover. An Excerpt from Captain Armstrong's Log.
"We've been in this Hrakert Rift now for almost 3 months, and our mapping expedition is almost complete. I can't say I'm sorry to see the back of it. The most we've actually found, was some odd fungus that was growing on an M Class world about 2 weeks ago. Despite that, this has been a rare excursion. There is a near abundance of M Class worlds in the region. A rarity, considering the Rifts properties, and the fact that some stars with an M Class Planetoid aren't typically found to be capable of supporting such a Planet. Yet here we are. More interestingly, is that none of the Planets we found are inhabited. Starfleet are definitely going to have a great deal of options to Consider for future Colonization efforts."
Before the end of the mapping expedition, Montana reached a planet, whose population initially appeared Pre-Industrial, but later actually turned out to be a highly advanced species who had given up their technological advantage, to keep their species hidden and isolated from the rest of the Galaxy. This Species, the Tekran, had at one point held a vast Galactic Empire, using their advanced technology to appear god like to all the primitive culture's they dominated. It was eventually learned that a combination with a symbiont species known as the Tyran's were responsible for the aggressive switch in the species nature.
Amongst the planets held by the Tekran's were Earth, Vulcan, Qo'noS, Andor, Bajor, Annex, and others, spanning an area ten times the size of the Federation, covering most of the Galaxy. The Tekran's, who'd overthrown their own oppressors in the Tyran Symbionts, had turned away from their aggressive nature, and back to peace, preferring to keep away from the rest of the Galaxy, hoping not to incur the wrath of the species they'd once subjugated.
In October 2383, the Starbase Deep Space 3 was attacked by 6 unknown Starships, and was nearly destroyed. Montana’s arrival, after receiving the stations distress call, prevented the Attack from continuing. After assuring that DS3 would be defended from any further attacks from this new threat, the Starship Montana pursued the aggressors. Despite the battle with the 3 Unknown Hostiles, little was learned about this new threat species, beyond the name - The T'raQan Union.
During the Battle, Montana was severely damaged, requiring extensive Refit. Montana’s Refit and Repair was conducted alongside Deep Space 3's Repairs.