COVID-19 testing at GC Fairgrounds Saturday, April 25 Posted in: COVID-19News Texas Health and Human Services is bringing a COVID-19 mobile testing site to Grimes County Saturday, April 25, from 8 a.m. till 5 p.m., at the Grimes County Fairgrounds, 5220 FM 3455 Rd, in Navasota. Tests will be conducted by appointment only. Those wanting to be tested will be screened prior ...PLEASE LOG IN FOR PREMIUM CONTENT. Our website requires visitors to log in to view the best local news. Not yet a subscriber? Subscribe today!