We dined at the dining room of the Lake Yellowstone Hotel on multiple occasions for both dinner and breakfast. Breakfast is offered as both a buffet and menu items. Anyone from a table can choose to order from the menu or visit the buffet, or both.
Dinner is also excellent. Large selection of various items ranging from typical casual dining to local cuisine. Local cuisine includes both elk and bison.
Would highly recommend a visit to the Lake Yellowstone Hotel dining room for at least one meal during your visit to the park.