I'll add to BadCat!'s gentle urging. I hope you find your kitty safe and sound (I assume you have checked with the shelter?), but do seriously consider keeping the cats inside. Roaming cats are one of the primary reasons for songbird declines in the US ... not to mention all the other health and safety reasons already mentioned.

Good luck.

A vet friend of mine told me 75% if his income is people letting their cats outside. Just sayin.

My cat once vanished for several weeks. He'd spent at least part of that time locked in our neighbor's sauna. He'd been a fat cat and came home gaunt. 

We stopped letting him out because a neighbor asked us to. He was crapping in her yard, which of course I should have realized he was doing. To the end of his days with us, he never stopped begging us to let him out. 

When we moved to Duluth we learned that it's illegal to let cats run free in the city. But it seems to be entirely unenforced. And I guess there's some justice in the fact that neighbor cats saunter over and poop in my garden. 

I hope your girl comes home, benne.

Just a note on letting cats outdoors. We've compromised with our cats. Part of our roof is accessible from a window, so I installed a portable screen with a makeshift pet door and they go out on the roof all day. They seem to really enjoy it and can't get into anything. They've never once tried to jump off or anything. We also put a harness on and attach them to the dog runner to play outside, but only when I'm outside doing yard work etc. This way they get enough of the outdoors experience to not complain too much, and they can't get into trouble. Some cat owners may be able to get creative about letting them enjoy the outdoors.

A roof or high/encolsed porch is a nice compromise for kitties that are mature enough not to get themselves in trouble. An extended walk (or rather, "follow the cat") on a harness is good as well. I've seen plans online for making a cat-proof enclosure, so depending on your yard, you could create a large enough space to keep her content and safe.

And I totally understand that you aren't looking for "you should have's" right now, you're looking to have your Bella home. I was unsure if I should bring it up to you, but decided that I should because I've lost cats and had cats harmed in this area. Our local vet told us that a lot of cats in Duluth's hillside are testing positive for feline leukemia (which is much worse than FIV, as it's super aggressive and much easier to transmit).

Again, my thoughts are for the health and welfare of Bella, and I hope that even if you decide to keep her an outdoor cat, she is returned safe and unharmed to you. 

We tried letting our kitty out on a harness, but he kept escaping. We never once saw him do it. We could see him in his harness from the kitchen window. He'd lie peaceably in the grass. But then at some point we'd look out there and there'd be an empty harness. 

I'm not saying the harness is a bad idea, but it was hilarious how badly it went with us. We never figured out how he did it. 

Let us know if Bella comes home!

Bad Cat! speaks the truth. We can't even keep collars on our kitties. They're little Houdinis.

My cats go out on long leads (ropes) with  harnessses that are generally escape-proof, unless they get seriously twisted around a vertical object (one of their hobbies)...I also made a tube out of cat fencing from "purrfect fence" -- closed with zipties and an opening at one end that closes with a rope...between these things they have fun and have never caught a bird. I am outside with them most of the time just to make sure all is well.

I just saw a coyote cross Woodland near UMD on my way home from a bike ride through Hartley.  I hate to say it but I think if there is a rash of missing cats in your area this is a likely culprit.