My most influential photography experience - How National Parks fail

I wanted to share a story about one of my first real experiences taking photographs on wildlife. At this point, I was not only trying to figure out how to take compelling pictures, but how to interact with my subjects respectfully. This experience helped shape the way I view wildlife photography and the ethics I follow every time I recreate in the outdoors and with wildlife.
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I spent about 2 days driving through Yellowstone National Park, searching for wildlife. I kept telling myself any animal I happened to see would be a treat, but in reality I had a list. At the very top, were Grizzly and Black Bears.
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It wasn't until day 2 that I saw any bears, having arrived too late the previous day. I was primarily searching the roadways and adjacent lands for Grizzlies, but they proved too elusive and the only glimpse I got was of one in the distance harassing a herd of Bison.
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I saw some bears about halfway through the second day. There were 2 Cubs, accompanied by their mother. I jumped out of the car and snapped close to 200 pictures. Soon, however, the sow and her Cubs were making their way over to the road way. I was over the moon with the pictures I was able to get with the approaching bears, but stared to notice some worrying behaviors from the mother in particular.
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The mother was clearly very anxious with the encroaching 200 bystander's and their vehicles so close. As the mother grew closer, I became anxious as well; not only because I left my car about a quarter mile away and was left totally exposed. It was becoming clear that the bears were trying to cross the road, but could not find a break in the mayhem to do so safely.
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One man said, "damn we should leave, I don't want to but it's the right thing to do." And then promptly got back in the car with his wife and drove off. Hats off to this nameless hero, it's hearting to know people with ethics still exist.
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Anyway, I decided without a ranger present the situation could turn sour quickly. People were becoming emboldened and were now standing as close as 12 feet from the mother, phones out trying to capture pictures of the distressed sow. The Cubs had climbed a nearby tree, clearly very scared of the ever growing crowd.
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Not having service to call a ranger, myself and an older lady from Alaska ran up the road to where the mother bear was pacing. She attempted to control traffic while I addressed some of the naive tourists that were too close to the bears. I yelled at one group and I must have looked or sounded like I knew what I was doing because they said sorry and backed away. However, our efforts were useless as more people continued to pile up.
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The cubs came down from the tree and the family seemed to start heading away from the road. I walked back to my car and turned around, hoping to find a place with service. I recognize now that is 100% what I should have done from the beginning. I ended up getting service down the road and told a ranger about the mother and her two cubs.
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In the end I captured some of nice photographs, but I also felt ashamed of my role in the whole mess. Not that it wouldn't have happened if I wasn't there, but perhaps next time we can all take a page out of the nameless hero's book, and simply remove ourselves from potentially harmful situations (to both people and the wildlife).
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I am also ashamed that national parks are supposed to be places for wildlife to thrive, the National park service itself says Yellowstone is considered pristine wilderness. However, it has clearly become a place for ignorant (myself included) tourists to come and FEEL wild without actually understanding the implications of their actions. However, it can also be places of learning, as it has been for me. If we can all learn something and try to be better next time, perhaps I can still think of these places as good.