Typically, snow removal contractors will stake between October and December to protect their properties. Now, it looks like everyone will be using snow markers in April. Wait, what? Check out this link, looks like snow is coming. Here is a photo of the rain from today and now snow is a possibility. Better late than never.
http://www.weather.com/outlook/weather-news/news/articles/snowstorm-destructive-northeast_2012-04-22