The Ruby Hill Rail Yard will soon open for urban snowboarding and skiing— even as temperatures are expected to near 60 degrees this weekend. Last week’s brief spell of subfreezing temperatures helped the city make snow, which will allow the free park to open on Sunday. A February open date is relatively late for Ruby Hill Rail Yard — in the last two years, it opened on January 26 after weeks of sporadic snow. Denver Parks and Recreation said the rail yard will stay open until March, weather permitting. Ruby Hill Park is open 5 a.m. to 11 p.m.