Was there any broad use of copper arrow-heads pre-Columbian?
Was there any broad use of iron arrow-heads post-Columbian?
How long did it take to transition to blackpowder weapons for non military use on the East Coast. If we need a specific place, then let's go with the Leatherstocking tales: up-state New York.
In areas where natural copper could be found the nuggets were cold worked by natives into a variety of tools including arrowheads. One of these areas was located around the Great Lakes and is called the Old Copper Complex. Copper arrowheads and other tools were also used in Alaska and the Yukon.
The use of copper was completely dependent on the availability of naturally occurring copper that did not need to be smelted.