Last year, Armstrong, who wrote the "Guide to Birds of Alaska" and "Alaska's Birds" suggested to the Juneau Assembly that it ban all hunting during late spring and summer near to the Mount Roberts trail.
Last fall city officials passed a law prohibiting hunting from April 15-Oct. 15 within one-quarter mile of the Mount Roberts Trail.
The 4.5 mile path begins off a stairway at the end of Sixth Street above downtown Juneau and used to be known as Father Brown's Trail for the Jesuit priest who built it in 1908 with a group of energetic volunteers.
The trail offers some of Juneau's best views and is perhaps the only place where the nesting ground of the state bird overlooks the state capitol, according to Armstrong.
The naturalist said the seasonal ban helps to keep people safe.
The Mount Roberts Trail and especially the loop at the top of the tramway are well traveled in the summer.
Some 200,000 people take the tram every year, according to tram owner Goldbelt Inc.
Many of them meander along the twenty-minute walk that starts behind the tram's mountaintop terminus and ends at the Nature Center.
Trouble is some hunters are unaware of the ban, said hikers and people who work around the tram.
The trail offers glimpses of marmot, bear and several different kinds of birds.
Naturalists observe that one of the drawbacks of the hike's popularity is that animals have become habituated, and less fearful of people.
Armstrong said the new law also helps to protect birds that haven't yet learned to fly.
Before it was passed last year, several young birds were killed close to the Nature Center at the start of hunting season.
"There were six broods of Blue Grouse, five broods of Rock Ptarmigan and one brood of Willow Ptarmigan-the state bird of Alaska--between the Nature Center and Gold Ridge.
After the opening of hunting season as near as I could determine from the feathers and shells and lack of birds being around, nearly all of them were shot," Armstrong said.
Some employees of the tram operation and the Nature Center point out that it's dangerous to hunt in the area when it's full of people.
Theresa Walden, who manages the Nature Center on behalf of Gastineau Guiding, says her staff has encountered hunters who appeared unaware of the new law.
"There were two people that went by the Nature Center, they were in camouflage gear and had an enclosed case that appeared to have a gun inside. An employee asked them if they knew about the ordinance prohibiting discharge of firearms and these folks went right on by and up the trail."
Walden said it's important to spread the word about the ban.
Juneau City officials are planning to install new, no hunting signs at the trailhead and at points along the trail in the next week.