I've walked through there during the off season.. HUGE park, I grabbed some pics of the first ~25 sites or so, and due to it being April and still 6" of snow on the ground, turned back towards the gate. I then found that those sites were the walk-in section, on a first come first serve basis. I'll see if I can find the pics, and post a few. I thought it was nice, from what I saw, only downside was it wasn't any better than the ~$12-$14 per night MA SPs, yet it was more than double the cost, with no more amenities.
FWIW, Lake Dennison and Otter River State Forest are about 20 mins from there, and im MA. Lake Dennison is beautiful, Otter River much smaller sites and not as nice of a park IMO, but they are within 5 mins of eachother, and run by the same rangers. Weird thing is, Lake Dennison closes Aug 31 , but Otter River is open until ~Columbus Day..
We camped Greenfield 4 time this year. 3 in a tent and most recently in new to us pup. Sites are large, wooded, and level. Beutiful lake for swimming, fishing, boating. Nice place to hike and bike. We have had a great summer at Greenfield, hope you enjoy it as much as we have.
We've been to Greenfield several times over that last couple of years. It's one of few NH state campgrounds in the southern part of the state that allow pets. The pet section is in the back of part of the main camping area.
As CT1701 mentioned, the sites are large, wooded and level. I went here first after buying our pup because of the space to maneuver the pup and it's close to home. There is only one bath house and it can be good distance if you're toward the back of the park but, there are several restrooms scattered through out the campground. All of these restrooms have power and hot/cold water. None of the camp sites have hookups. The roads through out the CG are paved. Bring your bike!
The lake is quite nice. I've canoed and fished there.
Rarely does this park fill up. Even during Labor Day, it did not fill (I checked - it was my backup that weekend).
There aren't as many activities outside of traditional outdooring (fishing, swimming, boating, etc - my kids like putt golf, go carts, etc). Peterborough is close by which we enjoy. If you're in the area in September and October, I highly recommend stopping along Rt 31 at Yankee Seige to watch the Punkin Chunkin'. It is impressive how far these guys can send a pumpkin with a Trebuchets. Check it out: http://www.yankeesiege.com/
We stayed there last September, the sites are flat, large and open, easy to get set up. Nice trails and lake. Also has a separate group area for Scouts and such. Close to home (Hillsboro), pet friendly. Will be taking advantage of Greenfield again.
Have camped there many times. Love it because it is within an hour from my home, there is a section that allows dogs, and nh parks are usually quite clean. My only issues have been holiday weekends tend to be rowdy and have experienced rude big rigs running generators most of the day on two occasions (note: depends on neighbors- can happen anywhere). Very wooded and large sites.
One great little tid-bit is that if you are a fan of Punkin' Chunkin, Yankee Siege is nearby. Must stop by and look at that beast of a trebuchet.