In cruise they'll fly from 60-120 knots. Ops - The greatest traffic conflicts are in the Isabella and Owens MOAs. Areas around Mojave and the Tehachapi pass are high threat. They should be high enough not to interfere with low-levels, but all intermediate flying could be affected. Since they fly as high as 18,000', gliders could even imact on refueling operations in the Isabella track.
Gliders are very small and difficult to see, unless they are in a turn and the wing is visible.
Radar will generally not pick them up, and they constantly change altitude and heading. In short - they are huge raptors made of metal tubing, plastics or fabric, instead of feathers and bones. They can easily bring down a jet in a mid-air. This page will maintain the latest information to notify and educate flight crews of any practices that are inappropriate in the parks. Please feel free to call us if you have any questions.