Sparks from Horse shoes

It *could* happen, but is not something I would consider an extreme risk. The only fire/explosions I am aware of with shoes sparking are in relation to the presence of other risk factors such as the extreme concentration of oxygen in hyperbaric chambers

Well your seeing the sparks which is all it takes to start a fire, but if you have ever tried to start a fire with flint and steel you'll know that it isn't that easy to do. You do need some good tinder, even dry grass can be hard to get going unless it is finer. But it is definantly possible. A gentleman that I worked for fixing fences on horseback years ago did tell me to watch where I rode and try to avoid the dry grass. I never started a fire but being as it was his property and he was paying me I also did what he said.
As for starting a fire from shooting yes I have done that one a few times. And shooting around dusk can help you to see it better as well. I think some of the problem is not necessarily the bullet lighting up but what you are hitting. And if your shooting tracer ammo you can really start some fires up. :) But never have I started a fire that I didn't put out and haven't shot a gun for a few years now so none of the ones this year were from me.

The rocks must be flint. I've never seen that happen but it must be cool.

The rocks don't have to be flint just have to have a hardness of 7 or so on the moh scale. Quartz would work and many other rocks of similar hardness to flint

Here in Arizona we have a lot of granite and sparks fly a lot! I've never seen a fire start from it, but in our extremely dry windy conditions lately better safe than sorry.

Gorgeous trails! Wow! If I ever get to your neck o' the woods, I'll be calling you.

There's burn marks on the concrete aisle where I board.

My then 4yr old was throwing a hellacious tantrum, slipped off the mats in the aisle, slid on the concrete which produced a shower of sparks and caught the loose hay on the floor on fire. Just happened that someone had left a partial bucket of water sitting a couple feet away, so I immediately doused it.

I'm in CO and things are beyond extremely dry here. I now sweep the aisle of any loose hay before putting my horse in the cross ties.

No flint around here. Lots of Quartz, Granite and compressed Shale
The Sour Dock and Cheat Grass are both pretty dry right now.

Love the beautiful pics. I would personally be very surprised if the small sparks from shoes would actually start a fire. But, stranger things have happened.