This may be the year to officially document the end of that ramp.
The October 2007 report by USBR titled "Final EIS - Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead" (
https://www.usbr.gov/lc/region/programs/strategies/FEIS/Chp3.pdf) shows the following critical elevations.
3,700 - Full Pool
3,620 - Castle Rock Cut closed; Hite Marina and Public Launch Ramp closed (obviously this was before the cut was deepened)
3,588 - Antelope Point Public Launch Ramp closed
3,580 - Main Bullfrog Launch Ramp closed
3,560 - Wahweap and Stateline Public Launch Ramps closed; Bullfrog Low Water Alternative Launch Ramp closed; Halls Crossing Public Launch Ramps closed
3,555 - Wahweap Marina closed; Antelope Point Marina closed; Bullfrog Marina closed; Halls Crossing Marina closed
Seems to me that all boats will need to be pulled from the water prior to hitting that 3,555 mark and that every (public) launch ramp is done at 3,560.
I really, really, really hope it doesn't come to that.
I realize this doesn't jibe with the known information on Halls Crossing at least with respect to minimum depths, so I am assuming it is not hard and fast at the 3,560 level, but I don't think we have options beyond 3,550.