OAKLAND (CBS SF) – Robert Doyle, general manager of the East Bay Regional Park District for the past decade and a fixture at the district for more than four decades, is retiring at the end of December.

Doyle, who started with the park district as a park ranger in 1973, is credited with being instrumental — in various positions within the district — in the preservation of tens of thousands of acres in urban areas for habitat preservation and recreation; for helping create the district’s regional trail system, including 200 miles of new regional trails; and expansion of parks in urban areas for multicultural communities, including increasing private fundraising for Regional Parks Foundation programs that help connect youth from underserved communities to nature.

READ MORE: COVID Omicron Variant: CDC Expands Surveillance To San Francisco International Airport

“Preserving land for parks on a large landscape scale has been something I’ve been passionate about and is worth fighting for,” Doyle said in a statement released by the park district.

The park district, comprising nearly 125,000 acres in 73 parks in Alameda and Contra Costa counties, and more than 1,250 miles of trails, more than doubled in acreage during Doyle’s 47 years with the district.

Robert Doyle (East Bay Regional Park District)

Robert Doyle (East Bay Regional Park District)

“Bob lives conservation,” Seth Adams, conservation director of Save Mount Diablo, said in a statement.

Save Mount Diablo is a Walnut Creek-based land trust and conservation organization working to preserve land on and around Mount Diablo (Doyle was one of the founding board members of Save Mount Diablo in 1971).

“John Muir is the East Bay’s most famous conservationist, but much of his work was elsewhere … Bob Doyle has been the most effective environmentalist in the history of the East Bay, with a greater positive impact on the physical geography than any other individual,” Adams said.

Diane Burgis, a Contra Costa County supervisor and a former EBRPD board member, said Doyle started out as an “activist to the core” and later became a “diplomat with an activist’s heart” who was able to make things happen.

READ MORE: San Francisco Bay Area Bridge Tolls To Jump By $1 On Jan. 1

“He was key to getting a lot of different (tax) measures passed that helped fund protecting open space, ” Burgis said in an interview, “and working to help get legislation passed that enabled saving open space.”

A key moment for Doyle was in 1979, when then-General Manager Richard Trudeau tapped him to head up creation of a regional trail system connecting its parks. Today, those regional trails — including the 13.5-mile Contra Costa Canal Regional Trail, the 26-mile Iron Horse Regional Trail and several sections of the San Francisco Bay Trail along San Francisco Bay — offer not only recreation, but also environmentally friendly modes of transportation for getting to work, school or shopping.

Other significant milestones during Doyle’s time at EBRPD include securing future parklands developments at three now-closed Bay Area military bases;  success, after a 20-year battle, to secure land along the Richmond shoreline, including the Dotson Family Marsh (named after the family who began the fight to acquire this property for the public) and the McLaughlin Eastshore State Park, co-managed by the district and the state; and increasing the park district’s connection with multicultural communities, including through the Regional Parks Foundation, a private fundraising nonprofit that improves park access for underserved communities, including communities of color.

“The landscape of the East Bay would be significantly different if it were not for Bob Doyle,” former EBRPD General Manager Pat O’Brien said in a statement. “Not only did he help create parks and preserve properties and areas for wildlife, but he inspired other people, who took up the mantel to advocate for open space, for legislative priorities within the district, and to procure public access.”

In his last year with the park district, Doyle led it through the COVID-19 pandemic, one of the most challenging times in its history.

“The district overcame tremendous challenges to keep parks open and safe for the public when they needed them most,” said Doyle, who credited the district’s relationships with the Alameda and Contra Costa health departments in helping accomplish that. “COVID-19 has shown just how essential parks are to the community’s physical and mental health.”

Finding someone with all of Doyle’s qualities will be difficult, Burgis said. “But I think the agency itself is so well-respected that some really good candidates will come forward.”

MORE NEWS: E.G. Daily On 'Rugrat's New Holiday Special "Traditions": 'We Embrace Everyone And Everything'

© Copyright 2020 CBS Broadcasting Inc. and Bay City News Service. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.