In context with our tour, we are often questioned about the danger going out from bears and sometimes we see ourselves confronted with claims that are wrong. Here's our take on the subject:

A grizzly in the open tundra of Brooks Range 2017. the animals are well visible and escape reliably as soon as they see a hiker.
The Brooks range is home to the "wildest" bears in the US. "Wildest" means that they are the least exposed to people or civilization. The animals are mostly grizzly and some black bear. The animals are smaller than in areas further south and the population density is relatively small with 2 Bears per 100 square kilometers. Nevertheless, encounters happen regularly: I (Manuel) have spent a total of about 30 days in the Brooks range and so far counted 3 encounters in the area including a bear with two cubs.
In Principle, Grizzlies fear people and flee as soon as they see you. Attacks usually happen when they feel threatened. Therefore bear encounters are dangerous when you surprise the animal. This happens mainly in thick scrub. Recommended measure is to constantly make noise when crossing such areas.
Like many other hikers in the Brooks range we will not carry a firearm because it is impractical and unnecessary. In the GOTA NP, there is only one known case of a deadly attack: in 1996 a hiker was killed by a bear in the thick bush along a river.
For possible encounters we will both carry a bear spray (310 ml Pepper Spray). They offer effective protection from bear attacks. However, they are no guarantee for safety. Since we mainly hike in open areas above the tree line, the chance of surprising a bear is rather low.
Undoubtedly the most important thing is that we do not store food near our tent and do not cook or eat in our camp. During the canoe section we will set up an electric fence around our camp to prevent bears from stealing our food.
By the way: Statistically, river crossings is far more dangerous than bears encounters. Therefore we have planned our route along the watershed to avoid large river crossings.
Reference: https://brooks-range.blog/2015/04/07/grizzly-bears-of-alaskas-brooks-range/