Every ski area operator shall:

(1) Mark all trail maintenance vehicles and furnish such vehicles with flashing or rotating lights which shall be in operation whenever the vehicles are working or are in movement in the skiing area.

(2) Mark with a visible sign or other warning implement the location of any hydrant or similar equipment used in snowmaking operations and located on ski slopes and trails.

(3) Mark conspicuously the top or entrance to each ski slope, trail or area to designate open or closed and relative degree of difficulty using the appropriate symbols approved by the national ski areas association as of the effective date of this article and as may thereafter be modified by the association.

(4) Maintain one or more trail boards at prominent locations at each ski area displaying that area's network of ski trails and slopes with each trail and slope rated thereon in accordance with the aforementioned symbols' code and containing a key to the code in accordance with the designations in subdivision (3) herein.

(5) Designate by trail board or otherwise which trails or slopes are open or closed.

(6) Place, or cause to be placed, whenever snow grooming or snowmaking operations are being undertaken upon any trail or slope while such trail or slope is open to the public, a conspicuous notice to that effect at or near the top of the trail or slope.

(7) Post notice at prominent locations of the requirements of this article concerning the use of ski retention devices. This obligation shall be the sole requirement imposed upon the ski area operator regarding the requirement for or use of ski retention devices.

(8) Maintain the ski areas in a reasonably safe condition, except that such operator shall not be responsible for any injury, loss or damage caused by the following: variations in terrain; surface or subsurface snow or ice conditions; bare spots, rocks, trees, other forms of forest growth or debris; collisions with pole lines, lift towers or any components thereof; or, collisions with snowmaking equipment which is marked by a visible sign or other warning implement in compliance with subdivision (2) of this section.

(9) When no certified ambulance service is available in the vicinity, have on duty at or near the skiing area, during all times that skiing areas are open for skiing, at least one trained and currently certified emergency medical technician.