A lot depends on what you mean by "good horse country" - and perhaps even more depends on your budget! I live in that general area (though I've not lived here long), feel free to PM if you want more info.
Not too much in Mercer County- I live further south so I don't know many small places but I know of 2 big show barns, Hunter Farms (princetonshowjumping.com) and Duncraven (duncraven.com) that are in Mercer County. Hunterdon which is the next county over has tons of farms. Very expensive area though.
I live right on the edge of the Hunterdon/Mercer line. Mercer County Equestrian center is a decent facility with some nice trail access. Board is very reasonable but stalls are virtually never available because of that. It is owned and run by the county so you can actually go ride there anytime, just drop off your coggins at the office and say hi so they know you are there.
Lots of horse stuff in Hunterdon, so I would aim to live towards that direction if you were thinking of moving here.
As other's have asked, what do you mean by "good" horse country. We have tons, and tons of vets, farriers, vet clinics, tack shops, horse shows in the area. There are several public parks that allow horses and there really is some nice trail riding to be had. But you would likely need a trailer for that and be capable of shipping and riding out on your own.
There are several public parks that allow horses and there really is some nice trail riding to be had. But you would likely need a trailer for that and be capable of shipping and riding out on your own.
Unless you board at one of the barns on the Amwell Valley Trail networks, or others... A lot depends also on where you want to live and how far you're willing to drive. Needs more info!!
Most of the horsey stuff is actually on the fringes of other counties -- Hunterdon, Middlesex, Monmouth, even Burlington. Depending on where in Mercer you live though, it's not a terrible drive to get there.
I grew up in the heart of Mercer and thought everything was suburb for the first 15 years of my life... Now I work/board 10 minutes away on the Mercer/Monmouth border and it's surprisingly rural. No, it's not as open as a place like VA, where I lived for a short time, but by the same token civilization is always right around the corner.
We get a little bit of everything, weather-wise: 120° heat index this summer, 3 feet of snow this winter. Spring and fall can be temperamental, but you usually have a clear idea of what season it is. The last few years have been pretty extreme.
Don't know ski areas personally, but have some friends that ski casually and make regular day/weekend trips throughout the season.
Freehold, Monmouth, Philly, and Chester tracks are all within an hour's drive from me. Meadowlands and Yonkers are about an hour and a half, traffic willing.
I have my complaints but it's really not a terrible place to live, in the grand scheme of things. Just depends on what exactly you're looking for.
The absolute best place to live near-ish Princeton if you have horses is East Amwell (e.g. Ringoes). Great trails, Amwell Valley Trail Association. Close to good equine clinic (Midlantic). Lots of farriers, vets, horse shows, but most of all, excellent trails. Lots of small "yuppy" horse farms (5 to 20 acres). Taxes way better (Hunterdon County) than in neighboring Mercer county. If you have 5 or more acres, can get farmland assessment (e.g. we had a place with 14 acres, 3/4 of an acre and the house was assessed "normally", $5000 or so taxes, the other 13 acres were farmland assessed, about $75 per year). Similar property in Mercer county would have been $12,000+ in taxes. This was all a while ago, so ramp up accordingly. It is only 20 to 25 minutes from E. Amwell to Princeton, so really close.