This study investigates the anatomy and plasticity of naive and stress haematopoiesis in mice. Researchers developed strategies to image multipotent haematopoiesis, erythropoiesis, and lymphopoiesis, combining these with imaging of myelopoiesis to define the anatomy of normal and stress haematopoiesis. In the steady state, stem cells and multipotent progenitors are distributed throughout the bone marrow near megakaryocytes, while lineage-committed progenitors are recruited to blood vessels to form lineage-specific microanatomical structures. This anatomy is resilient to insults such as haemorrhage, infection, and G-CSF treatment, and is maintained through aging. Production sites enable haematopoietic plasticity by differentially modulating numbers and output in response to insults. Stress responses vary across the skeleton: the tibia and sternum respond oppositely to G-CSF, and the skull does not increase erythropoiesis after haemorrhage. The study enables in situ analyses of haematopoiesis, defines the anatomy of normal and stress responses, identifies discrete microanatomical production sites that confer plasticity to haematopoiesis, and uncovers unprecedented heterogeneity of stress responses across the skeleton. The spatial organization of cells in a tissue dictates their behavior and function. Blood cell production occurs in the bone marrow through progressive differentiation of haematopoietic stem cells and progenitors. The bone marrow has extraordinary plasticity and quickly adjusts blood production to meet physiological demands in response to insults. Despite recent progress, the anatomical organization of normal and stress haematopoiesis remains largely unknown. This is because current approaches do not allow simultaneous imaging of most types of haematopoietic progenitors and their daughter cells, precluding in situ analyses of haematopoiesis. Overcoming this hurdle is essential for defining parent and daughter cell relationships and changes in cell behavior during differentiation, and to identify the cells and structures enabling normal and stress haematopoiesis. The study identifies key markers for visualizing haematopoiesis in situ and defines the anatomy of normal and stress responses. It reveals that multipotent HSPCs are spatially separated and enriched near megakaryocytes, while lineage-committed progenitors are recruited to distinct blood vessels. The study also shows that production sites for erythropoiesis and lymphopoiesis are distinct and non-overlapping, and that these sites adapt to stress in an insult- and lineage-specific manner. The results indicate that the basic anatomy of haematopoiesis is durable and resilient to acute insults, and that production sites orchestrate haematopoietic plasticity by adapting their numbers and output to adjust blood production to demand. The study also reveals that stress responses vary across the skeleton, with different bones responding differently to the same insult. The findings provide new insights into the anatomy and plasticity of haematopoiesThis study investigates the anatomy and plasticity of naive and stress haematopoiesis in mice. Researchers developed strategies to image multipotent haematopoiesis, erythropoiesis, and lymphopoiesis, combining these with imaging of myelopoiesis to define the anatomy of normal and stress haematopoiesis. In the steady state, stem cells and multipotent progenitors are distributed throughout the bone marrow near megakaryocytes, while lineage-committed progenitors are recruited to blood vessels to form lineage-specific microanatomical structures. This anatomy is resilient to insults such as haemorrhage, infection, and G-CSF treatment, and is maintained through aging. Production sites enable haematopoietic plasticity by differentially modulating numbers and output in response to insults. Stress responses vary across the skeleton: the tibia and sternum respond oppositely to G-CSF, and the skull does not increase erythropoiesis after haemorrhage. The study enables in situ analyses of haematopoiesis, defines the anatomy of normal and stress responses, identifies discrete microanatomical production sites that confer plasticity to haematopoiesis, and uncovers unprecedented heterogeneity of stress responses across the skeleton. The spatial organization of cells in a tissue dictates their behavior and function. Blood cell production occurs in the bone marrow through progressive differentiation of haematopoietic stem cells and progenitors. The bone marrow has extraordinary plasticity and quickly adjusts blood production to meet physiological demands in response to insults. Despite recent progress, the anatomical organization of normal and stress haematopoiesis remains largely unknown. This is because current approaches do not allow simultaneous imaging of most types of haematopoietic progenitors and their daughter cells, precluding in situ analyses of haematopoiesis. Overcoming this hurdle is essential for defining parent and daughter cell relationships and changes in cell behavior during differentiation, and to identify the cells and structures enabling normal and stress haematopoiesis. The study identifies key markers for visualizing haematopoiesis in situ and defines the anatomy of normal and stress responses. It reveals that multipotent HSPCs are spatially separated and enriched near megakaryocytes, while lineage-committed progenitors are recruited to distinct blood vessels. The study also shows that production sites for erythropoiesis and lymphopoiesis are distinct and non-overlapping, and that these sites adapt to stress in an insult- and lineage-specific manner. The results indicate that the basic anatomy of haematopoiesis is durable and resilient to acute insults, and that production sites orchestrate haematopoietic plasticity by adapting their numbers and output to adjust blood production to demand. The study also reveals that stress responses vary across the skeleton, with different bones responding differently to the same insult. The findings provide new insights into the anatomy and plasticity of haematopoies