LIVERMORE -- The day after Christmas, Mike Nicholson was to wrap up his last shift as the Livermore Area Recreation and Park District's ranger and naturalist supervisor, ending a 30-year career.

A self-proclaimed "Navy brat," Nicholson has always had an affinity for the outdoors. As a child, he often hiked and fished, spending hours exploring Hawaii's tropical rain forests.

Hired on by the district in 1982, Nicholson soon relayed his own enthusiasm for nature to local youth, introducing a junior ranger program the following year. Held on Saturdays for 9- to 12-year-olds, the program gave children the opportunity to hike and bike in the outdoors. It proved so popular, Nicholson started a companion program for older youth up to age 15.

Though the program's long-term goal is education, Nicholson said it more importantly instills an interest in nature in children to last a lifetime. Many of his former junior rangers continued on to become rangers, biologists, oceanographers and environmental lawyers.

"When I look back on my career, one of the more rewarding things is the influence I've had on these kids," Nicholson said.

In an era of budget cuts, LARPD board member Steve Goodman said Nicholson played a key role in maintaining the district's educational programs and continuing links to local schools.

"If you talk to people around Livermore, many of them were involved in that program," he said. "He mentored a lot of folks who were instrumental later on."

A graduate of Mission San Jose High School in Fremont, Nicholson attended the University of Utah, majoring in marine biology, and joined the Coast Guard as a marine science technician in 1971. He moved on as a park ranger in Fremont and later worked at Lassen Volcanic National Park and as an interpretive aide with the East Bay Regional Park District.

In March of 1982, Nicholson took a naturalist job with LARPD and was later hired on as their first ranger supervisor, overseeing the unit's day-to-day operations. Nicholson said he's pleased with the growth of the generalist ranger program; maintaining it, he said, is a "big deal."

"For a district of our size it's an important thing," Nicholson said. "With generalists, they do it all, so it's a really cost-effective way of operating."

Throughout his career, Nicholson was also a big believer in preserving open space. He was involved in acquiring the Brushy Peak Regional Preserve and in 1999 helped add 370 acres into Sycamore Grove Park. The district is in the process of annexing another 73 acres to the park. Nicholson calls Sycamore Grove, with its current 775 acres, a "significant asset."

"It's a wonderful park," Nicholson said. "It gives people in the community a place to go and escape the urbanism they have elsewhere, and it's so convenient."

LARPD board member Goodman credited Nicholson with playing a key role in securing the open space. Nicholson's hands-on style and expertise, he said, makes him difficult to replace.

"He comes with a wealth of knowledge, and that knowledge has been valuable," Goodman said. "His experience makes the position so unique. It's the end of an era in that respect."

At 61, Nicholson said he'll miss taking children on outdoor adventures, but he's not ready to fully retire yet. He'll pursue work with the National Park Service or the Oakland Zoo.

"I'm not the type of person who all of sudden can't have a place to go," he said.