I was also going to say the PNW. I live in the mid Willamette valley in and the closest event is literally 30 min or less from the barn I ride at the the furthest is 12-ish hours but the largest in our regend. Horses and horse property/boarding is reasonably priced. You can find a strong concentration of trainers who have competed in the upper levels in Washington (John Camlin, Anna Collier, Karen O’Neal, Ashley Loucks (John’s working student), Marc Grandia, Jordan Linstedt) are all on the I-5 corridor in Washington.
We regularly over book shows in Wa. Aspen, EI and Rebecca are generally filled within a few days of opening. Spokane, Caber and Young Riders Benefit also are full or close to full. The only one that tends not to fill is Inavale (it always tends to be 85-100 that weekend, without freaking fail). We have schooling opportunities typically staring in March (eastern Oregon and Washington. I can’t speak for Idaho or Montana), derbies and one days start in March/April and at least in Oregon there are 1-2 indoor schooling events in a large facility in Eugene that attract riders all the way up to BC.
Plus the beer/wine is pretty darn good.