Several devices fashioned from railroad spikes turned up in the Mojave Desert near California City on trails used by off-road riders and racers.
A Facebook post shows the dangerous spikes, warning that they were found along county roads behind the Castle Buttes.
The spikes in the desert are the most recent incident involving booby traps on OHV trails.
Riders in Massachusetts, Colorado, Arizona, Ohio and New Mexico also have reported manmade hazards on OHV trails.
The AMA urges anyone finding these hazards to photograph them in place and immediately contact the law enforcement agency in whose jurisdiction the traps were placed.
Photos and reports can also be emailed to firstname.lastname@example.org so the AMA can use them to publicize these threats.