Marek Petrik

Cool website: grndcntrl.net

Retweet if you care about @realDonaldTrump's tax returns

I'm choosing to #OptOutside with REI on Black Friday. Join me. optoutside.rei.com/?share_image=a… s3.amazonaws.com/reibins/c3d110…

Looking forward to #icml2016!

I would love to go for a European river cruise next year. Any recommendations?

@rkrguy Why do you think that?

@rkguy Any good ice climbing ideas? Is The Cascade in?