If you are outside anywhere near a thunderstorm, particularly a big plains beast, you are in some degree of danger. That said, "Risk is the price of life."
FWIW, my safety list.
1. Stay in the car as much as possible. (I don't always obey this, since I greatly enjoy being out in the storm to some degree.)
2. Lightning will go where it pleases. Don't count on a cliff, building, radio tower or anything else nearby to nicely 'suck up' anything headed your way.
https://www.flickr.com/photos/19806236@N00/4906066689/in/set-72157622800084513
If anything, tall objects can alter the local EM field and steer lightning gently in their direction,
without being struck. This lensing effect actually serves to concentrate the strikes in the ground area near the object! As you get closer, you may enter a genuine 'zone of protection.' Depending on the source you read, It extends only about half the object height from the object's base.
Squatting will lower your height by a few feet, and will fractionally reduce your chances of being directly struck. It's worth doing if you get stuck in a barrage far from cover, but heading for a safe building or vehicle is by far the better option.
3. Standing more or less directly beneath power lines is probably the one example of tall objects offering a significant increase in safety. Don't stand directly beneath, in case lightning somehow shatters an insulator - causing the whole mess to fall down upon you! And also stay well away from the poles, since the lightning will almost certainly be coming down them...
4. This brings us to the greatest lightning danger, 'ground current.' Ground current is responsible for the majority of injuries and deaths. (Direct strikes are rare, but are usually devastating.) A strike hundreds of feet away can potentially get you! Consider that the ground at the strike point has a potential of maybe 50~100 million volts. As the current dissipates, the voltage drops. Assume the ground 1000 feet away is a few thousand volts.... This generates an average voltage gradient of 50,000,000v / 1000ft = ~50,000 volts per foot in the ground you are standing on. If you happen to have one foot 6 inches closer to the strike point that the other, you suddenly have 25,000V (and plenty of current to go along) trying to crawl up your leg - rather a bad thing! To minimize this, make a habit of standing with your feet directly touching, and don't tough or handle anything near you (like cameras on tripods - LOL) Going further, I sometimes use a thick rubber mat with heavy steel screen glued to the base. Standing on this should (I hope) isolate me from some ground current danger. If I happen to be standing over a main 'channel' running through the ground, as seen at
http://weatherthings.com/LightningTrench.html I'm probably going to be zorched no matter what...