We always launched at Wahweap, or the nearby State Line ramp. The lake level currently is 3575, You need about 3585' level to use Castle Rock Cut. (saves going an extra 12 or so miles, around Antelope Island.).
Dangling Rope store and fuel is still closed. So you either have to carry enough fuel, water and food to reach Bull Frog or only go 1/3 of your fuel range.
Some prefer to launch at Bullfrog. It looks as if that is a little closer than Wahweap for you. The ramp was extended with the Sea Bee steel mats, Also the North ramp is available.
Also for exploration, it might be fun to go North from Bullfrog, to Forgotten Canyon Ruins (Defiance House) and explore canyons there, then go back to Bullfrog, refuel/water/provisions, and head south to the extent of your fuel (1/3 to destination, 1/3 to get back to the point of departure/fuel, and 1/3 reserve.).
Even thought this is lake, it can get mighty rough with certain winds. We heard the most "maydays" I have ever heart in one day during a Memorial Day weekend a few days back. Also beware of the flash flood, and falling rocks. There was a boat which was hit by a boulder and both occupants were killed. Cell phone is limited to where you can see Navajo Mountain, where there is a cell tower/repeater. Instant messages have a better chance of getting out. But we did always carried our Personal Locator Beacon or EPRIB. Spot and InReach would also work for distress or message contacts.
Have good anchoring gear, and also stern anchors or beach sand anchors. Have fun . September is generally a good month, but you can get sudden rain and winds. These can be dangerous, so be in a secure location, but not in a canyon where a flash flood would trap you.
