  In this paper we study highest weight and standardly stratified structures on
modular analogs of categories $\mathcal{O}$ over quantizations of symplectic
resolutions and show how to recover the usual categories $\mathcal{O}$ (reduced
mod $p\gg 0$) from our modular categories. More precisely, we consider a
conical symplectic resolution that is defined over a finite localization of
$\mathbb{Z}$ and is equipped with a Hamiltonian action of a torus $T$ that has
finitely many fixed points. We consider algebras $\mathcal{A}_\lambda$ of
global sections of a quantization in characterstic $p\gg 0$, where $\lambda$ is
a parameter. Then we consider a category $\tilde{\mathcal{O}}_\lambda$
consisting of all finite dimensional $T$-equivariant
$\mathcal{A}_\lambda$-modules. We show that for $\lambda$ lying in a {\it
p-alcove} $\,^p\!A$, the category $\tilde{\mathcal{O}}_\lambda$ is highest
weight (in some generalized sense). Moreover, we show that every face of
$\,^p\!A$ that survives in $\,^p\!A/p$ when $p\rightarrow \infty$ defines a
standardly stratified structure on $\tilde{\mathcal{O}}_\lambda$. We identify
the associated graded categories for these standardly stratified structures
with reductions mod $p$ of the usual categories $\mathcal{O}$ in characteristic
$0$. Applications of our construction include computations of wall-crossing
bijections in characteristic $p$ and the existence of gradings on categories
$\mathcal{O}$ in characteristic $0$.
