Lawmakers last year provided money to eat into the backlog.
On June 30, the backlog stood at 2,658 cases. It was at 2,095 on Dec. 30.
The department says it also has filled 31 of 36 vacancies within the Division of Mining, Land and Water since July 1, and done new employee training.
According to the division, the backlog has affected permits and authorizations for oil and gas, telecommunications, mining, commercial recreation, energy, small businesses and private individuals.