Section 1002.19 - Winter activities(a) Skiing, snowshoeing, ice skating, sledding, innertubing, tobogganing and similar winter sports are prohibited on Presidio Trust roads and in parking areas open to motor vehicle traffic, except as otherwise designated.(b) The towing of persons on skis, sleds, or other sliding devices by motor vehicle or snowmobile is prohibited, except in designated areas or routes.(c) Failure to abide by area designations or activity restrictions established under this section is prohibited.