House Or Rental
The best and cheapest places to stay can be found on Airbnb. There are tons of cabins that multiple groups of people can stay at (which will also bring down the price if you are splitting it).
Hotel
Here is a link to hotels in Twain Harte, if you would rather stay in a hotel rather than an Airbnb.
Flight
The Sacramento International Airport is a roughly 2 hour drive to Twain Harte so this option will include a car rental. If flights are too expensive and you don't want to rent a car you can also look into driving and seeing how far Twain Harte is from you.
Flight
The Oakland International Airport is also a little over 2 hour drive to Twain Harte, so this option will require a car rental as well. If flights are too expensive and you don't want to rent a car you can also look into driving and seeing how far Twain Harte is from you.