I've actually addressed a similar question before about this subject. You can find the start of my three part answer here:
Unfortunately a video link or two might no longer be available and my formatting for the sources is a bit wonky--apologies!
To add a little follow up, though... The late 1960s and 1970s were a time of major shifts of racial, ethnic, and for American Indians, political power structures. The Red Power Movement, as it came to be known, found itself lobbying for Tribal sovereignty and the assertion of Indian rights like never before. Of course, these kinds of movements were prominent at this time and many institutions were shaken to their core that allowed members of marginalized groups to capture national spotlights that were not available to them before. As backlash mounted against these sociopolitical efforts from entrenched hierarchies inhabiting the positions of power secured within these institutions, the American Indian Movement found itself leaning further and further into community defense and perceived militancy as a means to protect Tribal communities and advocate for Tribal interests. Doing so through the media was key as Natives made up a significantly smaller segment of the overall demographics of the United States and had to contend with additional political and legal barriers that applied to no other groups.
The examples of the Occupation of Alcatraz, the Siege of Wounded Knee, and the Incident at Oglala all served as major opportunities to highlight not only the efforts of the Red Power Movement and organizations like AIM, but the general presence of Native Americans located throughout all sectors of American society--not just on the reservations. These portrayals became necessary to generate the political capital necessary for American Indians to overturn the institutionalized oppression of Tribes by creating our image as not only a racial/ethnic group(s), but as nations who have retained our inherent sovereignty to dictate the futures of our peoples. Taking Alcatraz was predicated on the notion that the surplus federal lands should be returned to Tribes. Wounded Knee happened on the heels of fighting Tribal government corruption and federal paternalism. And the shootout at the Jumping Bull Complex on Oglala lands is a testimony to the political malevolence the federal government holds towards and our unique political nature within the United States (FREE LEONARD PELTIER!).
It became very apparent to proponents of the Red Power Movement that in order to generate that necessary capital, controlling our representation in the media was a high priority. But as my linked answer will show, these attempts to garner attention wouldn't always be within our control. The media as the double-edged sword that it truly is not only gave credence to our agitation, but it framed it as well. The more airtime American Indian activists got, the more convoluted the pictures became. Because we inhabit a unique position compared to other racial/ethnic/minority groups, a fair bit of context needs to be provided to properly understand said position. Tribes are sovereign nations who have reserved our inherent rights through treaties made with the United States federal government. This comes with a long history of legal complexities and political negotiations that aren't going to be accurately captured by your nightly news. At this time, it was common to paint Indians with broad strokes and frame us in ways similar to other civil rights movements occurring at the same time. And when Indians did get the airtime ourselves, focus was typically geared on producing pragmatic results to meet the immediate needs.
For example, the Fort Lawton Takeover that occurred in Seattle in 1970 had similar rationale to that of Alcatraz--federal surplus land should be returned to the Indians from whom it was taken. But the activists were seeking these lands to meet the crisis of Urban Indians suffering from high rates of poverty and neglect in this urban environment. So while the rationale slowly manifested itself in the long deliberations recorded by news outlets (particularly local and regional newspapers and reporting agencies), the immediate focus was shifted to the benefits of obtaining this land and was proclaimed by the Indian activists. In other words, they highlighted the desired outcomes over the articulation of the underpinning reasoning. While this had the effect of bolstering public support, it also meant that the Indians involved in the takeover were subject to the media's interpretation and observation. Thus you have headlines like, "Indians Drum Up Support for Fort Claim," "Indians Seized in Attempt to Take Over Coast Fort," and "The Indian Siege Of Fort Lawton." While many of the activists engaged in peaceful protest and civil disobedience, the presentation in the media fell victim to the stereotypes and tropes of the dominant culture. Attempts to occupy the fort were thus characterized as some sort of Western film beckoning to images of Indians attacking settlers and raiding forts. Ironically, this was even the case from the press that supported the Indian claims to the fort! (The anti-Indian opposition was much, much worse). But many of the activists did have access to these outlets. Notably the Seattle Times and the Seattle Post-Intelligencer were interested in capturing the Native Voice and thus many leaders got to provide commentary on the event. As previously mentioned, the development and explanation of the rationale gradually came out via media outlets, but many of the activists still took these moments to shift attention to producing outcomes rather than advertising concepts.
The example of Fort Lawton and the general utilization of the media at this time demonstrates well its positive and negative effects. But understanding its role when it comes to the portrayal of American Indians, AIM, and the actors who were able to center themselves in these presentations depends highly on the context surrounding the instances of portrayal.