Osteal macrophages (osteomacs) and osteoclasts have distinct roles in bone homeostasis but share common haematopoietic progenitors. Osteoclastogenic in vitro differentiation potential resides within the monocyte progenitor enriched Ly6C^hiCD11b^⁻ bone marrow (BM) fraction, but is retained by classical monocytes (Ly6C^hiCD11b^hi cells, also known as inflammatory osteoclast precursors). The Siglec1 gene encodes CD169, restricted to subsets of tissue resident macrophages (TRM). We used a floxed nuclear GFP (nGFP) reporter mouse to profile CD169-Cre targeting. The nGFP reporter is expressed in osteoclasts, osteomacs and BM TRM, despite osteoclasts lacking detectable CD169 protein. Reporter expression occurs in most TRM regardless of current CD169 expression, suggesting CD169Cre has lineage tracing characteristics due to activity in progenitors. Indeed, a small subset of classical monocytes (3+/-1%) in adult BM are the least mature cells to express nGFP. Both nGFP⁺ and nGFP⁻ classical monocytes have osteoclastogenic potential and differentiate into GFP⁺ osteoclasts in vitro. While CD169Cre alone does not enable TRM-specific targeting independent of osteoclasts, the nGFP reporter facilitated ex vivo identification of intact bone/BM TRM and enabled optimized isolation strategies of these cells for transcriptomic profiling. Bulk RNA-sequencing showed nGFP⁺ TRMs exhibit higher-fidelity transcriptional signatures than conventionally sorted populations, exposing contamination in publicly available datasets. This signature includes detectable expression of early-intermediate osteoclast genes (Acp5 (TRAP), Nfatc1, Atp6v0d2) and absence of mature osteoclast markers (Oscar, Calcr). These data could support dual recombinase-mediated intersectional genetic approaches to map plasticity between TRM and osteoclasts or achieve osteoclast-independent gene targeting in TRM.