The tricky part about identifying fly agarics in the northeast is that the local variety (
A. muscaria var.
guessowii) has very similar coloring to
Amanita frostiana.
A. frostiana can have some fuzziness around the base, but it doesn't present as clear concentric rings; sometimes it will have a very slight collar, either with or without the fuzzy texture continuing a little ways up the stipe. Typically (but by no means always) the cap is smaller in proportion to the rest of the mushroom than with
A. muscaria. The stipe often tapers towards the cap, while the width of the stipe is more consistent along the entire height with
A. muscaria. The annulus (the part that looks like a skirt hanging off the stipe) of
A. frostiana is more fragile than that of
A. muscaria and may fall off with age.
Spore prints examined with the naked eye are not a helpful indicator. Nearly every mushroom that looks like
A. muscaria will also have a white spore print. Examination of the spores under a microscope can be helpful though. In
A. muscaria, the spores are smooth, non-amyloid, and broadly ovate; they typically measure around 10 x 7 µm; clamps are often present at the bases of basidia. In
A. frostiana, Spores are globose to subglobose, typically measuring around 8.5 µm across; otherwise they are similar to fly agaric spores, being non-amyloid, and having clamps present at the bases of basidia.
The most helpful thing in getting a positive ID is to be very gentle with the base of the stipe when harvesting (so as not to damage or disturb the concentric rings) and to get high-resolution pictures of the base.
Other lookalikes to look out for in the northeast are
Amanita crenulata and
Amanita flavoconia.
A. frostiana is probably not toxic, and may even contain muscimol and/or ibotenic acid... still, I'd try to be assiduous in identification and avoid eating them. From your pictures, there are a couple that stick out as possibly being
A. frostiana:
(Especially the one on the right in that second pic)
I'm also suspicious about the coloring on these:
Then again the pigment could have been washed away by rain, and color isn't a very good indicator for identification anyway. It would be helpful to see some of the more important morphological features (shape of the stipe, close-up of the base of the stipe).