DENVER -- A high speed chase in Weld County ended with two people injured after they stole copper from a rural property.

Investigators say it is the latest example of how copper has become a hot item for thieves.

A passerby called police at about 7:30 am Thursday after witnessing the two men taking copper from the site.

The morning chase reached speeds of up to 80 mph before the two thieves were apprehended. They were taken from the scene and are expected to recover from their injuries.

Weld County Sheriffs Department spokeswoman Margie Martinez said the car involved was stolen, adding, "They did in fact have copper in the vehicle that we were able to recover."

The price of copper has tripled in the last couple of years, forcing many businesses to change how they operate. At HD Plumbing Supply they have moved their copper piping indoors away from drive- up thieves.

In California, a man was so frustrated by copper thieves he posted surveillance camera video on the internet and offered a $2,000 reward that leads to an arrest.

The thefts are also driving up construction costs. Not only do builders have to restock their copper supplies but they are paying to increase site security.

Building groups are holding seminars on how to protect their property. Even scrap pieces go quickly.

Julian Romero, the manager of a Denver plumbing supply company told 7NEWS,"A guy drove up and beat us to a pile of scrap copper, before we could get it on our own truck. He had copper sticking out all four windows and was flying down the road."

Colorado lawmakers are considering legislation that would require scrap metal dealers to keep better track of who is selling them material.