If you wish to establish these around your home, pick as many as you can, and bring them back to your home. You can just toss them on the ground in the areas you wish them to grow. Or, let them dissolve to a black goo in a
bucket, then fill the bucket with
water (unchlorinated) , mix and pour the water into the ground.
Shaggy Manes seem to like high-nitrogen soil. They often show up in yards that have been recently fertilized. So you may wish to try this in a highly-manured area, with lots of organic material.
Another thing to try is to dig up some of the soil where they are growing, and transplant that to a suitable location near your house.
These
mushrooms can also be cloned and grown on agar, grain and sawdust, then spawned to beds in your
yard, but that can get a little involved.