The name "Denali" references the highest mountain in Alaska, which also happens to be where Arby's wild-caught Alaskan pollock fish filets come from.
Arby's Meat Mountain (pictured) isn't listed on the menu but you can ask for it and get two crispy chicken tenders, 1.5-oz of roast turkey, 1.5-oz of ham, 1 slice of Swiss cheese, 1.5-oz of corned beef, 1.5-oz brisket, 1.5-oz Angus steak, 1 slice of cheddar cheese, 1.5-oz of roast beef, and 3 half-strips of bacon on a toasted bun. It'll cost you $10. If you mention "Denali-style" during the month of March, you net yourself a fish filet in there.
According to the chain, around 300 to 400 people scale the Meat Mountain daily.
Fish isn't available on the menu year round so the "Denali-style" Meat Mountain won't always be available.