Figure 9. Penetration resistance by depth as a function of reclamation treatments. Three depth bins were 0-15, 15-30, and 30-100 cm. Values are in Joules per meter. Bars denote 90% confidence intervals. Dotted line represents mean value of reference site. Data were collected in between July and September in 2018 -2020 from BNI Coal, LTD, near Center, ND USA.