Marshall is an unusually reliable site, especially in the summer. Beginning May 1 there are often 100 soarable days in a row. How high you get and how far you might go XC depend on your skill but also largely on the day's conditions. Southern California often has a temperature inversion that limits soaring to 300-600 meters over launch, but some days are much higher.
Marshall is most often blue thermals. Only occasionally are there clouds to fly with.
Be sure and get a site briefing from a local.
Other Marshall websites:
Jerome Daoust: http://www.expandingknowledge.com/Jerome/PG/Site/Marshall/Main.htm
USHPA AND (temporary) CSS membership required (20USD/ month)
> see: https://crestlinesoaring.org/join/
Access
Maps and directions at these web pages:
http://www.expandingknowledge.com/Jerome/PG/Site/Marshall/Directions/Airpark/Main.htm
http://www.flytandem.com/justmaps.htm
Shuttle info: https://www.supersaas.com/schedule/flytandem/twovans
Gene Embree (+1 909 260 0131): https://www.ridestolaunch.com (2022: 20USD ride)
Rules
ALL necessary info to be found here: https://crestlinesoaring.org/general-site-guidelines/
Summer conditions mid-day are usually very strong and can be dangerous. Dust devils blow through the LZ. Pilots are encouraged to launch after 5 pm on their first flight and work earlier as they see how they like it.
Sometimes sea-breeze fronts blow through, you can see them coming. And occasionally gust fronts from thunderstorms, though most thunderstorms form far enough back in the mountains as not to affect flying.
wx info: http://www.crestlinesoaring.org/weather
APPI International