The suspects, who were driving an ATV and side-by-side off-road vehicle, stole a Blackberry cellphone, a first-aid kit, a Honda water pump and a propane tank.
They also caused extensive damage to a packer, a loader and the landfill office.
The total value of the items and the damage they caused is estimated to be $15,000 to $20,000.
Sudbury Rainbow Crime Stoppers is offering a guaranteed $1,000 reward for tips received before midnight Aug. 21, if the information leads to an arrest.
The standard process for determining reward amounts will apply after this deadline.
Anyone with information is asked to contact police at 705-674-7511 or Crime Stoppers at 705-222-TIPS, online at www.sudburycrimestoppers.com or by texting TIPSUD and the information to CRIMES (274637).