The main reasons are:
- It was difficult to get there; the Great Plains at that time were not very easy to get to as they are nowadays. There were multiple obstacles on the way, and it was also far away from the eastern coast and southeastern coast of the country where most of the population was concentrated.
- It was not safe; this part was still not safe for traveling and living, and this was due to the big problems with the native population which the government hasn't been able to sort out just yet, so attacks and killings were a common occurrence in this part.