Grizzly Bear Attacks in the USA/Data

Location

Location	Risk Probability (%)	Odds Ratio
Alaska	0.00029	2.9
Yellowstone National Park	0.000037	0.37
Glacier National Park	0.0001	1.0
Other Lower 48 States	0.00005	0.5
Non-Grizzly Area	0.0	0.0

Risk probabilities are based on attack rates per visit or population exposure. Alaska’s rate (0.00029%) is derived from 29% of fatal attacks occurring there (). Yellowstone’s rate (0.000037%) is based on 1 in 2.7 million visits (). Glacier’s rate (0.0001%) is estimated from regional data (). Other Lower 48 states have lower rates due to fewer grizzlies (). Non-grizzly areas have zero risk. Odds ratios are scaled relative to Glacier National Park (baseline = 1.0) based on attack frequency data. [](https://dogsacademy.org/bear-attack-statistics/)[](https://www.nps.gov/articles/bearattacks.htm)[](https://dogsacademy.org/bear-attack-statistics/)

• Brown bear attacks on humans: a worldwide perspective
• Bear Attacks (U.S. National Park Service)

Activity

Activity	Risk Probability (%)	Odds Ratio
Hiking/Camping	0.00025	1.0
Hunting	0.00055	2.2
Working Outdoors	0.0002	0.8
Other Activities	0.0001	0.4

Risk probabilities are derived from a 2019 study showing 50% of attacks occur during leisure activities like hiking/camping, 24% during work-related activities, and 22% during hunting (). Hunting has a higher probability (0.00055%) due to stealth and attractants. Odds ratios are scaled relative to hiking/camping (baseline = 1.0). Probabilities are adjusted to reflect USA-specific data from 2000–2015 (183 attacks). [](https://www.nature.com/articles/s41598-019-44341-w)

• Brown bear attacks on humans: a worldwide perspective

Season

Season	Risk Probability (%)	Odds Ratio
August	0.0004	2.0
Other Active Months	0.0002	1.0
Hibernation Season	0.0	0.0

August has the highest attack rate (0.0004%) due to peak human activity and bear foraging (). Other active months (April–October) have a lower rate (0.0002%). Hibernation season (November–March) has zero risk. Odds ratios are scaled relative to other active months (baseline = 1.0). Probabilities are estimated from North American data (). [](https://www.eagleeyeadventures.com/blog/peak-grizzly-bear-attack-season-when-to-be-extra-cautious)[](https://www.nature.com/articles/s41598-019-44341-w)

• Peak Grizzly Bear Attack Season: When to Be Extra Cautious

Precautionary Measures

Precautionary Measures	Risk Probability (%)	Odds Ratio
Bear Spray and Food Storage	0.00005	0.25
Bear Spray Only	0.0001	0.5
Food Storage Only	0.00015	0.75
No Precautions	0.0002	1.0

Bear spray reduces attack success by 90% (), and proper food storage reduces attractant-related attacks. Combining both lowers risk significantly (0.00005%). Odds ratios are scaled relative to no precautions (baseline = 1.0). Probabilities are adjusted based on baseline risk from other tables and effectiveness data (). [](https://www.eagleeyeadventures.com/blog/peak-grizzly-bear-attack-season-when-to-be-extra-cautious)[](https://www.nps.gov/articles/bearattacks.htm)

• Peak Grizzly Bear Attack Season: When to Be Extra Cautious
• Bear Attacks (U.S. National Park Service)