Okay, a number of reasons why this comment and the ones below dont make sense.

1- No, it technically does not run on their property. It runs half a mile next to their reservation and through their ancient sacred grounds. But guess what, they dont live where they used to because we have been stealing their land for 150 years. Many tribes live hundreds of miles from where they originated because they were systematically removed, killed, and relocated.

As you can see, the American government has redefined what Sioux territory means a number of times. Namely through wars like the Black Hills War in 1877 (when General Custer discovered gold in the Black Hills.) Also, this reservation is only where the American government put all Sioux native americans after Red Clouds War, which in turn was caused by American government land grabs. (Source)(Source)
2- The fact this is not the only pipeline in the United States has literally zero bearing on the arguments. The argument is that the pipe runs through sacred lands, which will require construction and digging that will desecrate those lands. Second, it runs directly upstream of the reservation of the Missouri River, the Standing Rock Sioux's only source of water. Any spillage would contaminate their water supply indefinitely. And it only runs at this Missouri River crossing because the original plan, which would cross the river just north of Bismarck (the capital of North Dakota) was scrapped because politicians in the city forced the move. So the native americans in the area are now stuck with it. (Source)
3- Railroad accidents has nothing whatsoever to do with the potential of oil spillage from the pipeline. We are not talking about how many people this pipeline will kill, but that any spillage at any time would destroy the water supply of the Standing Rock Sioux for a significant period of time. It doesn't matter how few and far between they are, if pipeline spillage here ever occurs, it is an issue. And the list you offered still shows an extensive number of spillages over the last 15 years.
4- Most importantly, this is about respect and following the law. When it comes down to it, it doesn't matter whether or not the pipeline is truly dangerous to the Standing Rock Sioux or the sacred spaces (which it is.) What it comes down to is that zero respect has been paid to these people whose lives are being affected by the government (who are supposed to work for the people), and that they were not consulted properly as the law requires. US law that requires native americans to be consulted and included in any construction planning on or near ancestral lands