IDAHO

Its state capital is Boise (5)

Solution has appeared in 4 crosswords (2 across and 2 down):

• Quick crossword No 16,529 — 2023-04-27 23:00:05
  2D: Northwest US state (5)
• Quick crossword No 15,999 — 2021-08-16 23:00:01
  21A: The Gem State in the Rockies (5)
• Quick crossword No 15,423 — 2019-10-11 23:00:05
  21A: The Gem State, known for its potatoes (5)
• Quick crossword No 15,288 — 2019-05-07 23:00:09
  6D: Its state capital is Boise (5)