Just to begin with, but "hostile" and "peaceful" are perhaps unsuitable words for discussing the topic. Very few (if any) Native American groups were happy about losing their sovereignty to the U.S. A better way of phrasing it (which is what I assume you are asking about) is which groups violently resisted U.S. expansion as opposed to which groups resisted expansion politically or in other non-violent ways.

Additionally, we have to define what westward expansion is. I'll take the Mississippi as the border of the "West". Finally, this is a huge topic and I can't properly answer it since it would be the subject of many books, but I can give you some highlights. If there is any part of it you would be interested in hearing about more in depth you can certainly ask, or even post a new more specific question.

Just generally, if you are interested in the topic, these conflicts are generally lumped together under the heading of "American Indian Wars" or "Indian Wars". That said, these are conflicts involving many completely separate groups across more than a century (from even the Revolutionary War up until the early 20th century in the 1920s). Not all of these conflicts stemmed over Westward expansion, but very many did involve conflict between the U.S. military and U.S. settlers encroaching on Native American territory. There were other sources of conflict, but by far the most common was conflict between settlers encroaching on Native American lands, which often led to attacks by Native American groups and either preemptive attacks on Native Americans by the U.S. military or retaliatory attacks.

Many of the Native American groups living in the West today actually originate in the East. In particular, many of the groups living in modern day Oklahoma were forcibly moved there by the U.S. government from the Southeastern U.S. (Alabama, Arkansas, Georgia, etc.), including the Cherokee, Choctaw, Creek, and others. Oklahoma was originally the "Indian Territory" and set aside essentially as one large reservation to house all the Native groups forcibly removed from their lands in the East. Much of this removal was resisted through armed conflict or was the result of prior armed conflict, including the infamous Trail of Tears (a death march from the Southeast to new homes in the Indian territory).

Many of the nomadic groups living on the Great Plains and in the Rockies/Great Basin have a history of conflict with the U.S. government and U.S. settlers. In the Southwest (Arizona, New Mexico, Utah, and Colorado), various Ute, Apache, and Navajo groups all came into conflict with the U.S. government and U.S. settlers on multiple occasions for over 50 years starting after the U.S. annexation of large parts of the West from Mexico after the Mexican American war in 1848. These groups would often raid military forts and homesteads and ranches. The U.S. military infamously attempted to remove many of the Apache and Navajo from western and southern New Mexico/Arizona to a reservation in eastern New Mexico to better control them. The Navajo refer to the forcible removal to the Bosque Redondo reservation and Fort Sumner as the Long Walk, analogous to the Trail of Tears mentioned before. There is an excellent memorial and museum on the location of the reservation in Fort Sumner, NM if you are ever in the area.

Another famous conflict would be between the Apache leader Geronimo and the U.S. military, revolving around the settling of the Apache (of which there are several groups) on reservations at the end of the 19th century. This followed from other conflicts, including over the removal to Bosque Redondo earlier in the century.

In Texas and eastern New Mexico, and northwards on the plains, you also have a lot of conflict between U.S. settlers and the U.S. military and various Plains groups such as, most famously, the Comanche, but also the Kiowa, Cheyenne, and Arapaho. Quanah Parker would be a famous Comanche name from this period, and he and his family have had several biographies written about them as a way of talking about the Comanche wars through a more focused lens on a few individuals. You may also be familiar with the Cheyenne and Arapaho from the infamous Sand Creek massacre in eastern Colorado in 1864 where the U.S. army attacked a Cheyenne and Arapaho village. A name to know here is the Cheyenne military leader Roman Nose who lead much of the retaliatory military action against the U.S. military and U.S. settlers after the massacre.

The Sioux in the northern plains (the Dakotas and Wyoming/Montana) also had many conflicts with the U.S. military, most famously the battle of the Little Bighorn in 1876 were they defeated General Custer, as well as the battle and massacre of Wounded Knee where the U.S. military attempted to disarm the Lakota (the Sioux), but which ended in a lot of bloodshed.

Like I said, a huge topic and this is only the most general and brief overview of a few of the better known conflicts. If any of those sparked your interest, feel free to ask a more specific follow up question about it, ask for a reference, or even post a new question.