A yellow "Speeding Kills Bears" sign in Yosemite National Park, each sign marks a spot where a bear has been killed by traffic.
CNN  — 

Yosemite National Park officials are urging visitors to slow down after four bears were hit by vehicles in the last three weeks.

At least two of the bears were killed, and the other two were seriously injured, according to a park blog post. Two of the vehicles were going at least 25 miles per hour over the posted speed limit.

“It is important to remember that while traveling in the park, the posted speed limits are not only there to protect people, but to also protect wildlife in areas where animals cross roads,” the post said.

The PSA comes almost a year after the park designated several new Wildlife Protection Zones and clocked the speed of visitors in anticipation for last year’s labor day crowd. At that time, over 400 bears had been hit by vehicles in Yosemite National Park since 1995.

Every year, the park puts up “Speeding Kills Bears” signs to mark where bears have been hit or killed by vehicles. Some spots change year to year as new incidents occur but some mark frequent accident locations.

However, bears are not the only animals at risk, according to the park. Owls, Pacific fishers, butterflies, amphibians like red-legged frogs and salamanders, and other wildlife – such as deer, foxes and mountain lions – are also struck by visitors.

“While traveling through Yosemite, try to remember that we are all visitors in the home of countless animals, and it is up to you to follow the rules that are put in place to protect them,” park officials wrote.

Yosemite reopened in June after the coronavirus pandemic shut it down, but visitors must have a reservation to enter.