Colorado is a state located in the western region of the United States of America.
Sand Creek Massacre
In 1864, seven hundred men of one of the militias of the United States military slaughtered the peaceful village of Cheyenne in Sand Creek, killing and mutilating around one hundred Indians, mostly women and children. The militiamen waited for the men of the tribe to leave the village, and they attacked the families left behind to claim their land.
This event, later known as the Sand Creek massacre, was chosen by Trevor Slattery while masquerading as the "Mandarin" as a parallelism while taking authority of the bombing in the Ali Al Salem Airbase in Kuwait, as one of the "Mandarin's" lessons to the United States of America.
Kidnapping of Franklin Hall
S.H.I.E.L.D. decided to move one of his most prominent scientists, Franklin Hall, to a secure facility in an undercover but heavily guarded track, masquerading as a common supply delivery. Hall decided to leak the information regarding his route in order to be discovered by Ian Quinn, Hall's former colleague, so that Hall could approach Quinn's cluster of Gravitonium and destroy it. Under Quinn's orders, a section of the road near Sterling was seeded by Gravity Field Generators, in order to easily get rid of the vehicles that formed the convoy transporting Hall.
The transport went as usual, being Agent Mack the driver of the truck and having at least two vehicles escorting him. However, one of the vehicles suddenly was quickly lifted to the air, falling right in front of the truck, and Mack was forced to evade it, almost losing control of the truck.
Mack activated the truck's computers to calculate safe alternative routes, choosing the alternative route two, and informed the S.H.I.E.L.D. CT of the attack, however, he couldn't identify the attacker, and the truck was lifted just like the previous cars before it.
A group of men hired by Quinn arrived, using heavy construction equipment to dismantle the truck, and retrieved Hall, who was taken to Malta to meet Quinn in a country outside of S.H.I.E.L.D.'s jurisdiction.
Search for Franklin Hall
The team arrived at Sterling, explaining to newest recruit, Skye, the importance of a red-classified asset like Hall, and how the security should have been heavy, but seeing one of the SUVs that escorted Hall hanging on a tree made them think that something dangerous had attacked them.
Coulson and Melinda May interrogated Agent Mack, the truck driver, who told them that no attacker was seen in front, behind or above them, but what really worried him is that the attacker knew their route, insinuating that someone inside S.H.I.E.L.D. was working with the attacker.
Simmons discovered a gravitational anomaly in a specific place, having activated one of the Gravity Field Generators with the Electro-Static Field Scanner she was using. Once Fitz was able to deactivate it, Simmons retrieved the Generator and handed it to Coulson.
Grant Ward tracked the construction equipment used in the kidnapping, narrowing down the list of possible suspects to three names.
One of the suspects, Todd Chesterfield, hid at Barnroof Point following the kidnapping, but Coulson was able to track him down and confront him, as Chesterfield knew that the people who bought his excavator planned to use it for committing a crime.
Chesterfield threatened Coulson with a shotgun, but Ward, who accompanied Coulson and was out of Chesterfield's sight, managed to easily subdue him. Chesterfield confessed that he did not know the name or identity of the buyer, and that he was paid with gold bars. Coulson confiscated the gold, that served to figure out the identity of the kidnapper, Ian Quinn, as the gold came from one of his mines in Tanzania.