The 56-year-old Santa Rosa man who died Wednesday while cycling in Annadel State Park had ridden the park's trails for three decades.

Stanley Joseph Stawasz, a veteran printer who enjoyed both cycling and motorcyling, died of an apparent heart attack, his family said Friday.

The Sonoma County Coroner's Office conducted an autopsy Friday to determine why Stawasz collapsed Wednesday afternoon near the juncture of Marsh and Canyon trails in the park.

"He was doing what he loved when he died," said Brian Summers of Santa Rosa, Stawasz's brother-in-law. "He knew every trail by heart."

Stawasz rode in Annadel three or more times a week and "was in as good a shape as you could be," Summers said.

A passerby who found Stawasz unconscious attempted CPR with the guidance of a 911 dispatcher. Firefighters later took over, and unsuccessful efforts to save his life continued while Stawasz was flown by helicopter to Santa Rosa Memorial Hospital.

Born in Lemont, Ill., Stawasz came to Sonoma County in 1979. He had been a printer more than 30 years for O'Dell Printing in Rohnert Park.

In the early 1980s, Stawasz and Summers were among a small group of cyclists and equestrians who founded the Redwood Empire Trail Assist Group, which sought to help promote good trail use in Annadel.

He had been a member for 20 years of the North Bay Motorcycle Club. During that time he had helped initiate family enduro rides in the Mendocino National Forest that encouraged the participation of children and parents.

For 10 years he had volunteered with the National Motorcycle Patrol Medics.

He was quick to help others and "was always fixing things for people," Summers said.

He is survived by his wife, Kyrja Stawasz; daughters, Kaily and Leanne Stawasz; and a 1-year-old grandson, Anthony Hernandez, all of Santa Rosa. Other survivors include his mother, Agnes Stawasz of Santa Rosa; and three sisters, Chris Grodrian of Sebastopol, Fran Summers of Santa Rosa and Mary Jo Fiermonte of Weaverville.

An informal memorial service will be held at 7 p.m. Thursday<NO1>(co-March 29)<NO> at Daniels Chapel of the Roses. A Memorial Mass will be celebrated at 11 a.m. Friday<NO1>(co-March 30)<NO> at Resurrection Parish.

The family has established the Stan Stawasz Memorial Fund at Redwood Credit Union to provide for the education of his grandson.