This weekend, the Johnston Ridge Volcano Observatory opens for the summer season, starting with the annual Mount St. Helens Institute “It’s a Blast” event tomorrow. This is an all-ages, interactive event that will include elk viewing, interpretive talks, and a scientist-led hike along the Hummocks Trail. David Anderson will be signing copies of his new book “Images of America—Mount St. Helens,” and they’ll be demonstrating the new “spider” monitoring equipment that is being installed on the mountain. Other activities are also planned at the Science and Learning Center at Coldwater Ridge. Both facilities are open tomorrow from 10 am to 6 pm; admission is $8 per person. Proceeds will help support the Mount St. Helens Institute’s education and volunteer programs. More details are available on the Institute’s website.