These intensely purple plants lured me over the edge at Nufenen Pass. I wasn't in any danger, but I was the only person down on the ledge below the visitor centre. I just had to get a closer look.
The plants turned out to be Velvetbells Bartsia alpina. My field guide helpfully describes them as 'bright purple', in bold, like that, so you understand how very purple they are. They are also hairy.
This is a strictly upland plant, growing in wet alpine species rich pasture on steep banks and in flushes.