Help with encouraging potty on Leash?

Hi! We rescued a 1 year old female Husky, Kona, last week and are having some potty problems.

First, my partner drove Kona across country, from VA to CA. He found she would go in the backyards of friends' and at dog parks, but when he couldn't find a park on the way he walked her for over four hours with nothing. She held it for over 24 hours and we were really, really worried. But she went at the closest dog park the next morning asap. Once home, she had a few accidents. We take the positive training approach, so we clean up without fuss. I am pretty sure the accidents were her finally feeling comfortable and able to go. Plus, the areas she went on have had potty accidents before from our Aussie/lab. So we bought a different product to help with any smells and our home is having the carpet pulled up for hardwood this week and they spray down the floorboards to also help.

I took her on a 2.5 mile walk first thing in the morning: Nada. Take her on a 3 mile walk in the evening when she would potty: Nope. I take her and our other dog out together and when he goes, I praise him and give him a treat to help encourage her: nope. These are not short walks, at least 45 minutes because both dogs need the exercise for their breeds.

Since those accidents we have kept her successful by taking her to the dog park. The first few times, she would play until she couldn't hold it and then go. Now, she'll greet and play for a few minutes. I then say to her "Go potty, Kona." and she promptly walks to one of the grassy area she likes and goes. I praise her in a calm way and give her a treat. We have not had any accidents since and have successfully kept her on a morning poop and pee, 5-6pm poop and pee, and a late night pee. But she will NOT go on a walk. On the plus side, she is exhausted from all the park trips and walks and I believe a tired dog is a happy dog! She is able to socialize on a level she really hadn't before and we enjoy working on basic commands like come and sit with all those distractions.

Some have mentioned a longer leash, we have used a 4ft, 6ft, and 10 ft leads with her. I encourage her to sniff and explore in bushes and etc but to stay out of yards (we have lots of hedges and such on the little piece of land between the sidewalks and the street). I have tried with her harness and without. We've tried all different weights of collars. All the leashes are different weights, none are retractable. When we pass a spot another dog has gone and the owner did not pick it up or it's a pee spot, I encourage her and say "Good potty spot!". I also took her on a big walk yesterday up and down every street in our part of the neighborhood to help her get to know the area and smells. She does pull a bit, but she has quickly figured out she'll either have to go the other way or sit and let it go because whatever she really wants to see or sniff, I'll let her if she doesn't pull me. I figure a lot of it is she isn't use to going on leash and the more I take her, the more likely she will go.

Any advice or tips for encouraging a pup to go on leash will be greatly appreciated.

A tired dog is not necessarily a happy dog. They can feel absolutely dreadful if they are very tired. As to the going to toilet. I had a collie that wouldn't go all day at a show and wait until he got home. Eventually she will go but only when you stop stressing about it. You haven't had her that long and she needs to get to know you for a bit longer before she knows you won't get cross with her. Where ever she goes she has to feel comfortable with and not be pressured into it. I suspect she was probably told off at irregular times and now needs to know when that is right in her mind. As long as you carefully show her oustide where you want her to go if she has an accident indoors she will soon get to know that outside is where to go, whether it is in your yard/garden or on a walk.