The Issaquah Alps are a low (generally 2000-3000') range of mountains east of Seattle, WA.  They include several popular day hike peaks, such as Mailbox Peak, Mt Si and Mt Teneriffe.  The Issy Alps 50k, 100k and 100M were established by George Orozco as FKT routes for adventurous souls, as reported in Trail Runner Magazine.  A website outlines the routes and the "rules",

Paul Bradford posted this route near Logan, UT, which has a Strava segment:

Justin Walker submitted this 500+ mile road route.  For an FKT across the state any route would be allowed.  Here's what Walker did:

Also known as the Carpathian Arch, this is a 2000 km route that runs the length of the Carpathian Mountains, between Orszów (Romania) and Bratislava (Slovakia).  The route & previous crossings are listed here:  http://lukaszsupergan.com/kto-kiedy-jak-dlugo-statystyka-lista-przejsc-luku-karpat/