Hello, my name is Mike and I live in a small ranching area in south central Idaho. I have recently picked up a 4 yr old mare that the previous owners had said would be a good horse for my youngest daughter since I didn'l feel comfortable putting her on a ranch horse (she's 10) The problem I have is when you try to bridle her she is notorious for throwing her head and trying to back out. I have used cottom ropes behind her and pinching her neck to lower her head, a rope behind her shoulders, between her legs to her head stall and she stills fights. Looking for some help here. Other than that she has a great disposition and will let my daughter do anything with her. I even have a fight putting on a bosel...Anything will help since she does seem like a good horse for her and like everywhere, budgets are tight...Thank you

First, I wouldn't tie her up while bridling her. You might want to try just putting the lead rope on her face for awhile. Every time she backs away from you putting the lead rope on her face then lunge her for a few circles. Do this until she's good with the rope wrapping around her ears and nose ect. Also get her ok with the lead rope going in her mouth like you would put a bit. Once she's good with that then grab the bridle and just try bringing it close to her face. Again, when she trys to avoid you send her out on the lunge line. Make her trot fast or canter (no lazy circles). At first all you're aiming for is to get her ok with the bridle being brought to her face. Once you can get her past that then you can go to hanging the bridle off her ear, ect. Basicly I would treat her like a head shy horse or a horse who'd never been bridled before. The idea is to convince her that avoiding the bridle is more work than getting bridled. Also there is the age old advice of having your vet check her mouth and back (although it dosn't sound like a health problem seeing as she won't even let you put the bosal on). hope this helps.

Check her teeth. My guess is that she has a tooth problem and somebody starting forcing the bit into her mouth. She is now probably trained to throw her head in defense of this.

I would agree with NW. Have her teeth looked at..even if she is tossing her head with just a halter..it could very well be from a bad pr painful experience with a bit.
I would then work with her on the head down cue until she has it down pat.
I would avoid using a tie down as in my experience, it only exaserbates the problem..if you find you must use something, try a martingale..but only long enough to teach proper headset, no longer else they tend to start leaning on it.

Have you checked her ears for ticks, or her poll for sores? She could have a tick really far down in there, or wound that is causing this too. How does she act when daughter is on her about the bridle? Is she responsive, or not.
Did she do this the first time you bridled her, and did prior owners say anything about this? They may have hit her teeth or gouged her in eye when putting bridle on, or been rough in some way, or they may have taught her this is how you get bridled.
Or, she may have been beat about head, knew a Hackney pony once that some groom had taken whiffle ball bat to head and ruined her, great pony, but you had to dismantle bridle to get ready for show/training.
I would try carrying bridle in hand behind curry comb, soft brush, work up neck to head, ease up when she tenses, gradually getting to where bridle is doing the "grooming" and she has accepted it. Don't talk to her much about it, as may make her thing this is a BIG deal, oh no. If there are any treats she likes, apples, carrots grain, hold them where she would have to reach through headstall to reach, but don't make any sudden moves, don't try to catch her up and bridle, just get her used to getting near briidle/rope on own. Again, don't yammer at her, no good girl or yah yah yah, just be quiet and ignore her, as if it is natural for her to be close to bridle.
Rub up and down her forehead with bridle in hand, scratch all the good spots, and then walk away. Let her mull everything over, repeat as often as can in day, if can only do once, fine.
Do her as if you were teaching her to load, slow quiet repetition, matter of fact attitude, and not a lot of talking, and no fussing.
Might try molasses/honey on bit when slide in mouth, don't pull up, just slide it in let her hold it, and tell her to drop it. Also when you slide bit in, tell her to open, or take it. Give command so she knows what's coming. Stop and go back a step any time she gets antsy.
Keep doing this, getting higher and higher, working on rubbing side of face, base of ears, insides until she is desensitized to bridling, and always check that bridle is let out to comfort area, even if have to tighten.
It's time consuming, but this is a young mare, and the extra time will be worth it, as she and your daughter have lots of years ahead.
Good luck.