Why was there no place for Native Americans in the West after the Civil War?

After the Civil War, more Americans went West.  Many Southerners, their lives ruined by the war, looked for fresh starts in the Western states.  Many African-Americans went North looking for factory jobs, but several also looked West of the Mississippi for a land that might possibly have less discrimination.  More Americans took advantage of the Homestead Act of 1862, which meant that someone could own land only by living on it and making improvements.  Congress allocated money for the Transcontinental Railroad project; the railroad was completed at Promontory Point in 1869.  Soon, there would be other branch railroads linking to this and other transcontinental railroads.  The railroads employed millions of workers and these workers often needed professional buffalo hunters.  In addition to killing all their food supplies, Americans moving West also looked at taking the West's resources.  Miners rushed from claim to claim, looking for silver and gold.  Cattlemen treated Texas, Oklahoma, and Kansas as their own pastureland until homesteaders came and fenced the area for their own.  The U.S. also saw increased immigration from Europe after 1865--these new immigrants often preferred the West because the railroads sold them the land cheaply and advertised it heavily in the Old World.  Due to economic development and the growing U.S. population, the Native American lost land quickly.