Answer the question at the end by quoting:

Plains Indians, Interior Plains Indians or Indigenous people of the Great Plains and Canadian Prairies are the Native American tribes and First Nation band governments who have traditionally lived on the greater Interior Plains (i.e. the Great Plains and the Canadian Prairies) in North America. Their historic nomadic culture and development of equestrian culture and resistance to domination by the government and military forces of Canada and the United States have made the Plains Indian culture groups an archetype in literature and art for American Indians everywhere. Plains Indians are usually divided into two broad classifications which overlap to some degree. The first group became a fully nomadic horse culture during the 18th and 19th centuries, following the vast herds of buffalo, although some tribes occasionally engaged in agriculture.
The nomadic tribes historically survived on hunting and gathering, and the American Bison was one primary resource for items which people used for everyday life, including food, cups, decorations, crafting tools, knives, and clothing. The tribes followed the seasonal grazing and migration of buffalo. The Plains Indians lived in teepees because they were easily disassembled and allowed the nomadic life of following game. When horses were obtained, the Plains tribes rapidly integrated them into their daily lives. People in the southwest began to acquire horses in the 16th century by trading or stealing them from Spanish colonists in New Mexico. As horse culture moved northward, the Comanche were among the first to commit to a fully mounted nomadic lifestyle. This occurred by the 1730s, when they had acquired enough horses to put all their people on horseback. The Spanish explorer Francisco Vasquez de Coronado was the first European to describe the Plains Indian culture. While searching for a reputedly wealthy land called Quivira in 1541, Coronado came across the Querechos in the Texas panhandle. The Querechos were the people later called Apache. According to the Spaniards, the Querechos lived "in tents made of the tanned skins of the cows (bison). They dry the flesh in the sun, cutting it thin like a leaf, and when dry they grind it like meal to keep it and make a sort of sea soup of it to eat....They season it with fat, which they always try to secure when they kill a cow. They empty a large gut and fill it with blood, and carry this around the neck to drink when they are thirsty." Coronado described many common features of Plains Indians culture: skin tepees, travois pulled by dogs, Plains Indian Sign Language, and staple foods such as jerky and pemmican. The Plains Indians found by Coronado had not yet obtained horses; it was the introduction of the horse that revolutionized Plains culture. By the 19th century, the typical year of the Lakota and other northern nomads was a communal buffalo hunt as early in spring as their horses had recovered from the rigors of the winter. In June and July the scattered bands of the tribes gathered together into large encampments, which included ceremonies such as the Sun Dance. These gatherings afforded leaders to meet to make political decisions, plan movements, arbitrate disputes, and organize and launch raiding expeditions or war parties. In the fall, people would split up into smaller bands to facilitate hunting to procure meat for the long winter. Between the fall hunt and the onset of winter was a time when Lakota warriors could undertake raiding and warfare. With the coming of winter snows, the Lakota settled into winter camps, where activities of the season ceremonies and dances as well as trying to ensure adequate winter feed for their horses. On the southern plains, with their milder winters, the fall and winter was often the raiding season. Beginning in the 1830s, the Comanche and their allies often raided for horses and other goods deep into Mexico, sometimes venturing 1,000 miles (1,600 km) south from their homes near the Red River in Texas and Oklahoma.

Where did the nomadic tribes live?

their homes near the Red River in Texas and Oklahoma.

Answer the question at the end by quoting:

Glucks was born 1889 in Odenkirchen (now part of Monchengladbach) in the Rhineland. Having completed gymnasium in Dusseldorf, he worked in his father's business, a fire insurance agency. In 1909, Glucks joined the army for one year as a volunteer, serving in the artillery. In 1913, he was in England, and later moved to Argentina as a trader.
Just a few days after the Wannsee Conference in January 1942, Himmler ordered Glucks to prepare the camps for the immediate arrival of 100,000 Jewish men and 50,000 women being evacuated from the Reich as labourers in lieu of the diminishing availability of Russian prisoners. In July 1942, he participated in a planning meeting with Himmler on the topic of medical experiments on camp inmates. From several visits to the Auschwitz concentration camps, Glucks was well aware of the mass murders and other atrocities committed there. Correspondingly, Auschwitz Kommandant Rudolf Hoss routinely informed Glucks on the status of the extermination activities. During one of his inspection-tour visits to Auschwitz in 1943, Glucks complained about the unfavorable location of the crematoria since all types of people would be able to "gaze" at the structures. Responding to this observation, Hoss ordered a row of trees planted between Crematorias I and II. When visits from high officials from the Reich or the Nazi Party took place, the administration was instructed by Glucks to avoid showing the crematorias to them; if questions arose about smoke coming from the chimneys, the installation personnel were to tell the visitors that corpses were being burned as a result of epidemics. In 1942, the CCI became "Amt D" of the Wirtschafts- und Verwaltungshauptamt (SS Economic and Administrative Department; WVHA) under SS-Obergruppenfuhrer Oswald Pohl. Glucks continued to manage the camp administration until the end of the war. Therefore, the entire concentration camp system was placed under the authority of the WVHA with the Inspector of Concentration Camps now a subordinate to the Chief of the WVHA. According to historian Leni Yahil, Glucks was "the RSHA man responsible for the entire network of concentration camps" and his authority extended to the largest and most infamous of them all, Auschwitz. From what historian Martin Broszat relates, nearly all the important matters concerning the concentration camps were "decided directly between the Inspector of Concentration Camps and the Reichsfuhrer-SS." In January 1945, Glucks was decorated for his contributions to the Reich in managing the fifteen largest camps and the five-hundred satellite camps which employed upwards of 40,000 members of the SS. Glucks' role in the Holocaust "cannot be over-emphasized" as he, together with Pohl, oversaw the entire Nazi camp system and the persecution network it represented.

What were Glucks thoughts about the murders?
Glucks complained about the unfavorable location of the crematoria since all types of people would be able to "gaze" at the structures.