Yup. My last job was at a large corp and one of my previous managers was in his late 50's, having been there since he graduated college. He was a bit of an exception, but we had many people in their 60's & 70's who had been there for decades.

I left after 15 years.

Yes. They're all over. They just aren't venture capital funded valley start ups.

Both major organizations I've worked in have had ridiculously low turn over and everyone I talked to in both had the assumptions of everyone being lifers. I only left the first because I was tired of doing maintenance on old technology and wanted to experience new dev.