They are not dangerous.
They are wolf spiders.
They are scary looking.
When I moved into my home 6 years ago, the yard was overrun with those spiders.
when you mowed the lawn, if you stopped, you could see them running around on the ground.
I bought some bug/spider spray at Lowe's that you spray on your yard/house containing Diazanon (?).
It attaches to your garden hose and mixes in the spray bottle, while spraying.
After spraying the entire yard, twice over a couple days, there were no more spiders for a couple years.
Now, I apply once a year.
Being sure to spray the hell out of the areas around the house, and on the house very thoroughly.
Obviously, this is more of a preventative, than a cure. But it will work over time, as they stop living and breeding on your property.
The spray will mean less food for them, too.