According to Kenny Moore's Sports Illustrated story Gerry owned a running shop in California, Oxnard maybe, called Gerry Lindgren's Stinky Foot. Supposedly the shop was doing well. But there was some sort of possible legal difficulty and one day he left his wife a note telling her to sell the shop. That was, at the time of the article, the last she or the kids saw or heard of him.
It seems no one else did either. He just vanished. Years later, I don't know how many but it was a few, runners in Honolulu began bumping into a guy who bore a lot of physical resemblance to Lindgren who called himself Gale Young, I believe that's the name in Kenny's article. Some of these runners struck up conversations with him and Young would have stories of having run really good races against some one time big names. I probably should go to the SI Vault and dig this story out but don't have a lot of time now. For a time he clung to being Gale Young and denied knowing anything about "that Lindgren guy" but eventually he acknowledged who he was to someone, I think Moore, they knew each other well from their best years. I'm a little vague here.
This not a normal sort of marital split story. Do you stay and fight for your kids if you've got some sort of legal problem breathing down your neck? Do you do it if you think you're a really bad parent and husband and the rest of the family would be better off without you? I know of a situation where that was the case. The obvious response here is "learn to be a better parent and stay involved" but not everyone can do that or believes he can.
So you're right. There more to the story than gets mentioned here when Lindgren is a thread topic here. As far as I know Gerry has never discussed this situation and it seems unlilely he ever will and maybe for that reason he's responsible for the criticism he gets here.
To the 200 mile weeks, I'd guess they weren't precisely measured but would be in that range, maybe more. People did that sort of thing then. One of Lydiard's good but lesser known runners was a guy called Jeff Julian. He was actually one of the pre race favorites for the '64 Olympic Marathon but did not do well. When it was base time for Arthur's guys and they were getting in about 1,000 miles in ten weeks Jeff was doing 2,000. He worked as a banker and would run a full marathon before work and another 10 miles afterward. This was not a one week thing. It's what he did for that entire ten weeks.
Lou Scott ran the 5,000 for the US in the '68 Olympics. He says he ran 50 miles a day in two sessions to do that, 35 -45 in the morning and 10-20 in the afternoon. That would work out to the 350 mile week we see attributed to Lindgren. Take all this for what you want.