The roads were closed, they had steel gates across them. It was reported that unknown persons had cut the chains and locks and had opened the gates. However, no one checked to see that the gates remained closed.
The gate was open, BLM officials would later acknowledge, because the bureau had failed to follow normal procedure and close it for the winter.
I too had initially heard that someone had cut the chain and left the gate open, but apparently BLM finally fessed up here to not doing its job. Typical government apathy...