LOL well when I read the first post the first thing I thought of was - oh yes younger ones! I don't think most older women are going to lie about it. But then again, there are those who have the whole slut shaming fear thing. I could care less and most women I know are about the same about it. We are way past dealing with guys who have issues about such things. If they do, cool, NEXT.
I really can't answer the question of where to find mature women. I think it depends on what you are asking. I know a lot of women who go for younger guys but then they are doing it for fun, not for a relationship. A few may be thinking relationship....especially as it seems so many men are having ED issues and such. I do know there are a lot of single older women out there who are looking for/wanting a relationship and some really don't want all the baggage and the set in the ways things that come with some older men. I can tell you when I used to go to things with meetup.com there sure were a lot of single older women (in groups that weren't dating based, but were for singles) The travel groups and various get together things had tons. Aren't there some older single moms around your son's activities/school? I find there are quite a few out there....many started having kids later or have a big age gap in their kids. Lots of 40+ single mama's out there.
Here's the thing though....you need to make sure you know how to treat a woman well and be able to pull off the old school gentleman treatment, or you aren't going to get far. Chivalry goes a long way. I know on this forum the men seem to hate that hearing that - but you either do what works to get the results or you have a bunch of excuses...you know?
Other possibilities are business related activities, going back to school, etc. Cultural events, art shows, museums.....depends on the type of woman you are talking about. Certain bars if you are into that. Yoga studios, Starbucks, quaint restaurants......