It hasn't happened yet, but very well could.

Scottsdale is looking to buy the land and they are looking for public input as to how that land should be used and "the types of recreational uses that the city might restrict on the land". We know that mountain bikes will be one of those uses that "some" people want to restrict.

If you want some say in this they will be discussing the issue at 5 p.m. Aug. 6 at the Granite Reef Senior Center, 1700 N. Granite Reef Road (just north of McDowell Road)

Details here:
http://www.scottsdaleaz.gov/News/07-27-09.asp