Many years ago the local game warden would get salt blocks paid for with County fine money as a result of F&G. Coming out of winter the coats of the deer would look real rough and they were heavily invested with ticks. To make the fine money go a ways he would buy the white salt blocks. There were a few key locations the blocks would go. One was at a high elevation fire lookout. Normally I was the first guy into the area in the spring knocking down remaining snow drifts.
Below the lookout was the place the salt blocks had been placed for many years. In the spring visible evidence of a block was gone but the deer had the area dug up. A few days after I had the tower opened for the season the lookout arrived. The Lookout/fire watch had over fifty years of experience at this and other lookouts. One of the first things she told me was to buy a block of Yellow Sulpher Salt when in town. She said the deer recovered from the winter faster and it knocks the ticks.
http://www.tractorsupply.com/livestock/livestock-salts-minerals-milk/livestock-salt/block-sulfur-salt-2516528The tower was a great place to observe deer behavior. At the time the area had a very high deer population because of the rapid regeneration after a forest fire a few years before. Within week of placement of the salt blocks the deer were looking better. The yellow block was placed about 15 feet from the white block. The deer would push and crowd the yellow block and it quickly went down. The white block would get attention when a deer could not get to the other.
There were a number of range allotments in my unit. The ranchers would put out salt blocks where they brought their cattle out on the range. Normally they would put out white salt blocks, but I would occasionally see mineral and sulfur blocks. I felt the Sulpher blocks were hit harder by deer, or I might have been prejudice from my observations at the lookout, and the testimony of a fine lookout who had observed deer on salt for many years. Months later when the hunting season open the salt block was removed.
(Bless Orva; she passed away in her lookout in her later seventies. The lookout was torn down a few years later, a victim of dry rot, and termites.)
P.S. using a salt like to bait or attach deer in many states is illegal including California. Diseases that infect deer herds are often passed from one animal to the other from slobber on a salt lick or food source.