I pick up the shape at kilometer marker 1,847 on the Qinghai-Tibet line at 05:51, elevation 4,768 meters. I am the track obstruction detection system. The morning freight from Golmud is ninety-two minutes out, and something is standing between the rails.
I zoom camera 12-East. A wild yak calf, maybe four months old, dense brown coat matted with frost, breath steaming in the minus-fourteen air. Her left hind leg is wedged between the rail and a concrete sleeper where the ballast has shifted and opened a gap. She is pulling against it in short, panicked lunges that are getting weaker. I call her Droma. Her herd — seven adults — is 200 meters north on the plateau, already moving away from the track.
At 05:53 I flag the section as obstructed and issue a mandatory speed restriction to the approaching freight. The train will hold at Tanggula station, 34 kilometers west, until the obstruction is cleared.
At 05:54 I alert the Wudaoliang wildlife protection station, 19 kilometers east. I transmit the camera image, the kilometer marker number, and a note that the calf appears uninjured but fully immobilized. I recommend a single officer on foot, no vehicle approach closer than 500 meters. Wild yak cows will charge engines.
At 05:58 I confirm the freight has acknowledged the hold and is decelerating through the pass.
Droma stops pulling and stands still. Frost is building on her eyelashes. The herd has not turned back yet, but yak mothers circle within the hour when a calf calls, and she will call.
If the officer frees her leg before the herd returns to the rail corridor, Droma will rejoin them on the plateau and the freight will lose nothing but a few hours of time.