It felt up by the sheathed boulders .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 It)) (VP_4 (ATVP_3 (VBD_2 felt) (PRT_0 (RP_0 up))) (PP_1 (IN_1 by) (NP_2 (ATNP_0 (DT_0 the) (VBN_0 sheathed)) (NP_4 (NNS_1 boulders)))))) (DOT_0 .)))