Grizzly bears and Brown bears are technically the same species, Ursus arctos. The distinction between these two mammals is based on where they live and what they eat.
“Grizzly bears” are also brown bears, but as their habitat is on mountain slopes, tundra plains and inland forests they are typically smaller in size than coastal bears because their food source is quite varied and less plentiful than along the coast. Grizzlies live in the Interior and Arctic regions of Alaska, such as Denali National Park and Gates of the Arctic National Park. They tend to eat roots, grubs, and small rodents. Because of the difficulty in finding an abundance of food, grizzly bears tend to be smaller and more aggressive than brown bears. The term “grizzly” comes from their fur’s color, with gray typically on their shoulders and hump. “Grizzly” is not in reference to “grisly” or horrific.
The term “brown bear” is the common term for bears found in coastal areas. Their habitat includes rich grassland and salmon filled streams offering a bountiful food source. You will find “brownies” in coastal areas of Alaska, like Lake Clark National Park or Katmai National Park. Brown bears typically feast on fatty salmon in the summer, as well as clams and sedge grass. Their consistently plentiful food supply allows them to grow larger than grizzlies and appear to be a bit more fat and happy. They will still violently defend their cubs and their space, but they don’t generally see people as a meal or competition.
So providing you don’t do anything stupid, it’s relatively safe to be observing or photographing these coastal brown bears in a place like Katmai National Park, as their attention, for the most part, is on finding salmon. Hiking in an area like Denali is a very different story.