Every lawman needs a partner, and Don Zimmerman's is a 17-year-old buckskin quarter horse named Skeeter.
Zimmerman, 78, is a member of the Pasadena Volunteer Equestrian Unit, an unpaid and unarmed group of riders selected by the Pasadena Police Department to patrol on horseback through isolated stretches of the Arroyo Seco that are difficult or impossible to patrol by car.
"Basically they're reserve police, but non-sworn, who can write citations and are trained with Mace," said Lt. Gregg Henderson of the Pasadena Police Department, who, with now-retired Lt. Wesley Rice, was instrumental in getting police reserve status for the unit in 1985.
In the Arroyo Seco, the unit's 16 members give warnings and citations to people with unleashed dogs, mountain bikers on the horse and hiking trails, and transients living outside the authorized camping areas. Police have caught drunken and disorderly visitors and even flashers after the riders radioed in their descriptions.
The unit's presence alone serves to discourage activities such as spray-painting graffiti on rocks and trees, said Patrick Phillips, 32, a three-year member who patrols areas in the northern Arroyo Seco such as Oak Grove Park and Devil's Gate Reservoir.
"I think our main objective is to sort of police, not so much with guns and clubs but with eyes and ears," Phillips said. "We're out there to create a presence and to try to deter any activities that would make the arroyo undesirable."
Members are issued a hat, shirt, belt and saddle blanket bearing the blue-and-gold emblems of the Pasadena Police Department, but receive no other compensation.
Each equestrian patrols the Arroyo Seco an average of 30 hours a month during spring and summer, when public use of the arroyo peaks.
The unit seeks recruits who are at least 21 years old, know how to ride and have access to a horse, although some unit members will share their mounts, said Lt. Betsy Bour, the unit's highest-ranking volunteer.
Applicants should call the administrative section of the Pasadena Police Department. They must complete an interview and submit to a thorough background check.
Horses must also prove that they are qualified for the work. "Some horses just don't do well on the trail at all," Bour said. "Some horses have done only ring work, and out on the trail every blowing branch scares them."