I knew Donald L. Gibbon a little. In Pittsburgh it was hard not to, if you traveled in environmental circles or paid attention to the local-food movement.

Gibbon was active in both. I saw him most frequently at environmentally themed events, such as when he testified passionately at a public hearing last year about mountaintop-removal coal mining. The force of his testimony belied his thin frame and sometimes labored speaking voice, the result of the throat cancer he'd battled for years.

Don was very active with the Sierra Club's Allegheny Group. The last time I spent more than a few minutes with him was this past spring, when (at his invitation) I spoke at the group's monthly meeting about a wilderness canoe trip I'd taken. He even gave me a ride home afterward.

But I met Don through the Apple Fest, which he founded, and which will take place for the fifth straight year this Sat., Oct. 23, despite Don's death, on Oct. 13.

Don, 73, lived in Point Breeze with his wife, Linda Bazan. In his professional life, he had a multifaceted career in electron microscopy, teaching geology and more. He was an accomplished photographer. And he was as opinionated about apples as he was about preventing environmental degradation: He started the festival, he said, because you couldn't get a good apple pie in this town. The problem, he said, was largely the homogeneity of the commercial apple supply, exemplified by the ubiquitous red delicious.

One goal of the festival was to reintroduce people to older, lesser-known but much tastier varieties of apples, like the Stayman and the Connell Red. In fact, the last time I interviewed Don, just last month, it was about his initiative to bring to Pittsburgh 10 young Black Amish apple trees (www.pittsburghcitypaper.ws/gyrobase/Content?oid=oid%3A85932). 

The Apple Fest was never a one-man show. But Don's death definitely leaves big shoes to fill.

"He was one of a kind," says Virginia Phillips, a friend of Don's and a co-founder of Slow Food Pittsburgh, which co-sponsored the fest.

This past Wednesday, Phillips said that "an army of volunteers" was mobilizing to handle many of the details and errands Don would have managed. Folks like Claudia Kirkpatrick, she said, were picking up apples from 10 orchards to be sold at the event, held 11 a.m.-2 p.m. at the Union Project, 801 N. Negley Ave., Highland Park.

For a $5 entry fee ($2 for students and kids 12 and under), fest-goers can sample apples and cider from area growers.

As in years past, the event also includes live music and other entertainment; treats like locally sourced pulled-pork sandwiches and ice cream; and of course the famed apple-pie contest. (Winners will be announced at 12:30 p.m. There's still time to enter; see www.slowfoodpgh.org for details.)

"The only thing that's missing is Don," says Phillips.