Where is a good place to meet mature, single women over 30? I don't go to bars and live in a small town.

Church groups, and honestly if it is a small town, then normally someone you know, knows someone else.

And you meet women daily, at the store, at the bank, gas station.

HI,
Good anwers before mine!
A small town is also the type of environment I live in, but personally not looking myself. I am 64, married many years.
Friends would be your best bet in a small town. They will know most of the single women over or around 30. As mentioned, Food Stores, Church, etc.
Is there a "singles" group in your town? Maybe a group that meets once a week to go out for dinner?
Also, is there a nearby town, within driving distance, that you could check out?
Some online "personals" are free, such as http://www.matchdoctor.com
Check it out. A widowed friend told me about it, and he has already met someone from a nearby town, in person. Don't know how it's going yet.
Best of luck.

Try some recreational activities such as bowling leagues (seek out one that's mixed with a lot of single women), square dancing or country line dancing. Also try a church group if you're so inclined (many offer activities for single adults.) You could also try personal ads or online matchmaking services such as eharmony.com. Also don't overlook your married friends or relatives as networking sources. Some of them are bound to know some single women that they could introduce you to.