Im travelling to Austin, Texas (from Australia) through LAX from Good Friday through to the 8th of April. Ive got a work conference in Austin from March 30th to April 1st but have spare time either side (5 days before / 7 after).

Ive been to America quite a bit (49/50 states) but never this time of year. My questions are:

What National Parks etc would be best to visit that time of year that are close to either LA or TX (or feasible in the time frames elsewhere)?
Whats Yosemite/Kings Canyon going to be like over the Easter long weekend?
I dont mind kooky/obscure stuff so if theres anything around Texas worth checking out, please suggest!

Ill most likely be renting a car so public transport isnt a limitation. Thanks!