My neighbor is luring them in with corn!
Idaho Dept. of Fish and Game have no rules prohibiting the feeding of elk, however, some cities do have ordinances that prevent feeding of wildlife or feral pets within their city limits. Be aware, if a private citizen artificially feed big game, you could be liable for damages caused by those animals to surrounding neighbors private property and landscaping. Damage is common because the animals become concentrated and are more likely to browse on shrubs and be involved in accidents with vehicles - especially cars and snowmobiles, when in the city limits. When you draw wintering elk into close proximity, you are also drawing large predators that prey on wintering elk (wolves, mountain lions) into the city, as well. This can be a real problem for your neighbors and our agency.
Most elk don't need artificial feed to survive - especially in a mild winter like we are experiencing in Idaho. Elk employ several different strategies to conserve energy including a reduction in metabolism and using thermal cover to minimize energy expenditures to maintain their core body heat. Our employees monitor wintering elk and if they actually need artificial food to survive, we have the mechanisms in place to feed a diet that can be utilized by elk.
Feeding is a last resort for several reasons. First, artificial feeding draws elk off of natural winter range. If they become accustom to artificial feed and the food is taken away, starvation can occur. Second, when you concentrate animals diseases are more likely to spread throughout the population because they are in closer contact. Last but not least, concentrating elk, like other ungulates, leads to major damage to the environment where they are concentrated. Be prepared to spend significant amounts of energy and money to clean-up the site once the elk leave.