The movie heavily implies it, but is Kurt Russell's Michael from 3000 Miles To Graceland really the secret son of Elvis Presley? Kurt Russell and Kevin Costner were two of the biggest actors of the 1980s and 1990s and famously went head to head with competing Wyatt Earp movies. Costner was actually attached to Tombstone at one point before leaving over creative disagreements, and once Russell became attached to the latter, Costner reportedly used his clout and blocked most avenues to the rival movie getting produced.
Russell's Tombstone ultimately proved both a critical and commercial success, whereas Wyatt Earp became a box-office dud. The duo later teamed up for 3000 Miles To Graceland, a heist movie where they played criminals who rob a Vegas casino during an Elvis convention. The movie had a great supporting cast too, including Courteney Cox, Christian Slater, Ice-T, Thomas Haden Church and many more. The movie pitched itself as a hip Tarantino-style crime thriller with some John Woo-influenced action, but the end product was something of a fascinating mess.
3000 Miles To Graceland is an uneasy mix of crime thriller, comedy, and bloody action movie, complete with a blend of classic Elvis tracks and nu-metal music. It's an odd blend that never fully gels - but it's also never boring as a result. The movie also teases that Russell's Michael and Costner's Murphy are the sons of Elvis, with Thomas Haden Church's federal agent revealing the latter was part of a group of 75 men who tried to prove they were the illegitimate children of Elvis. Church's character also states that while 73 were ruled out, two were inconclusive.
3000 Miles To Graceland later shows Michael finally reaching his beloved boat, where he reveals to Cox's character was left to him by his father. He's shown briefly holding a golden record before revealing "I didn't even know him." This is certainly enough to imply Michael was indeed one of the men whose DNA test proved inconclusive, but all doubt is removed when the final scene reveals the name of the boat is "Graceland," essentially confirming Michael is indeed the son of Elvis.
Of course, this sets up an interesting dynamic between him and Kevin Costner's Murphy. They're initially shown as friends until the latter betrays him, and Murphy is also portrayed as utterly obsessed with Presley. Murphy's parentage is never confirmed in 3000 Miles To Graceland, but the idea the duo could be half-brothers is also woven into the story. Given that Russell has played Elvis three times - and even starred alongside Presley in his movie debut in 1963's It Happened At The World's Fair - it's not controversial to state he's the best impersonator of the two actors.