Train traffic ground to a halt for most of Wednesday in Grand County because of a major rockslide in Gore Canyon.
 
Repair crews were forced to use explosives to blast several large boulders to re-open the railway.
 
An Amtrak passenger train bound for Emeryville, California, in the San Francisco Bay area, had to be halted in Granby.
 
A second passenger train, the eastbound California Zephyr, was delayed west of the canyon.
 
Nine freight trains were also halted.
 
The railroad was alerted about 10:00, Wednesday, that something had happened along its tracks in Gore Canyon west of Kremmling, said Mark Davis, a Union Pacific Railroad (UP) spokesman.
 
What sparked the alert was a break in the railroad's slide detection fence, which is an electric warning system positioned along the railroad in mountainous areas.
 
UP Railroad maintenance crews were immediately dispatched to investigate the problem in Gore Canyon.
 
There they discovered that several large boulders had fallen onto the tracks.
 
Informed of the problem, dispatchers with the railroad radioed the message to the trains scheduled to go through the canyon.
 
Due to the size of the boulders, the UP crews had to blast to make them smaller so they could be moved off the tracks, Davis said.
 
Some damage to the tracks had occurred and needed to be repaired.
 
Davis said the railroad expected to be able to open the tracks through Gore Canyon by 19:00, Wednesday.
 
Will Bublitz.