If it isn't, it should be.

You need to call your electric and/or utility provides to confirm, but they general rule is no "permanent" structures, meaning a removable faux bolder would be fine. I am also in MA and the neighborhood next to me has underground utilities. The unfortunate thing is that they very infrequently need to visit these boxes, but when they do... they slaughter anything in their way, which is understandable.

Many of the residents of the neighborhood planted really nice shrubs that had been growing for a decade without interruption, then this summer they had to upgrade all the utilities and all the plantings were trashed. Lesson Learned.

I hate the way they look also, and also thought if it was in my yard I would use those fake rocks plus tall perennially grass...then no problem if/when it's time to visit the box, just lift the cover and cut the grass.