Two motorcycles and a grey Peugeot 2008 collided on the A6 at the Edge Brow junction on Sunday afternoon (April 3).
One of the motorcyclists – a man in his 50s from the Lancashire area – was declared dead at the scene.
The second motorcyclist – also in his 50s and from the Lancashire area – was taken to hospital with life-threatening injuries.
He remained in a stable condition in hospital on Monday morning (April 4), police said.
Officers investigating the collision urged anyone who saw the crash – or the moments leading up to it – to get in touch.
They would also like to talk to hear from anyone who has dashcam footage.
Anyone with information can call 101 or visit cumbria.police.uk, quoting incident number 118 of April 3.
Alternatively, independent charity Crimestoppers can be contacted anonymously on 0800 555 111 or online at crimestoppers-uk.org.