It Sounding with face-up over the boulders for the waist-high boulders .
(ROOT_0 (S_0 (ATS_3 (NP_0 (PRP_0 It)) (VP_2 (VBG_0 Sounding) (PP_2 (IN_0 with) (NP_3 (NP_5 (NN_3 face-up)) (PP_2 (IN_0 over) (NP_3 (NP_6 (DT_0 the) (NNS_1 boulders)) (PP_0 (IN_1 for) (NP_5 (ATNP_1 (DT_0 the) (JJ_1 waist-high)) (NNS_1 boulders))))))))) (DOT_0 .)))