A sign at an unsupervised shooting site near the Catalina Highway northeast of Tucson urges shooters to “put an end to trigger trash” — but not all shooters heed the message.

The site, on national forest land fewer than 200 yards from the highway, is less littered than it was two years ago, but shot-up targets, shell casings and discarded drink bottles still make this a far-from-pristine parcel of public land.

“Recreational shooting is an acceptable use of national forest land when done safely and responsibly,” said Heidi Schewel, spokeswoman for the Coronado National Forest. “Shooters and other forest visitors who leave trash and debris behind are not acting responsibly and detract from the enjoyment of the forest by others.”

Environmental group leaders and activists say the site near the 4.4-mile point on the Catalina Highway is one of many areas on public lands where irresponsible shooters have had a negative impact on the landscape.

“Irresponsible shooting activities have increased on public lands,” said Sandy Bahr, director of the Grand Canyon Chapter of the Sierra Club. “Shooting of saguaros and other vegetation is a real problem in some areas, plus people haul all kinds of stuff out to the public lands, shoot it to pieces, and then leave behind the trash as well as shell casings.

“If they are shooting (at) electronics, there are heavy metals that can contaminate the soil and, of course, there is also the lead from the ammunition,” Bahr said. “Contamination of the soils is definitely a concern.”

Cyndi Tuell, an attorney and environmental activist, said she is dismayed by the actions of many shooters.

“I’m beginning to question whether there is any such thing as ‘responsible target shooting’ on public lands,” said Tuell, who is a Green Party candidate for Pima County Attorney. “Every single place target shooting takes place, we see trash, bullets, destroyed vegetation and contamination.

“People who shoot on our public lands are making it clear they cannot follow the rules, and they should be prohibited from destroying our lands,” Tuell said.

“They are poisoning our lands with lead and other toxic chemicals, and we cannot tolerate this any longer.”

Bahr called for stepped-up enforcement.

“Overall, people need to understand that if they abuse the lands, there are consequences,” she said.

“Better information and education is helpful, but it must be coupled with enforcement, so that those who flaunt the laws and show no respect for the beautiful public lands we are so very lucky to have in Arizona are caught, fined, and their privileges revoked.”

Contact reporter Doug Kreutz at dkreutz@tucson.com or at 573-4192. On Twitter: @DouglasKreutz