  Young stellar populations provide a powerful record that traces millions of
years of star formation history in the solar neighborhood. Using a revised form
of the SPYGLASS young star identification methodology, we produce an expanded
census of nearby young stars (Age $<50$ Myr). We then use the HDBSCAN
clustering algorithm to produce a new SPYGLASS Catalog of Young Associations
(SCYA), which reveals 116 young associations within 1 kpc. More than 25\% of
these groups are largely new discoveries, as 20 are substantively different
from any previous definition, and 10 have no equivalent in the literature. The
new associations reveal a yet undiscovered demographic of small associations
with little connection to larger structures. Some of the groups we identify are
especially unique for their high transverse velocities, which can differ from
the solar velocity by 30-50 km s$^{-1}$, and for their positions, which can
reach up to 300 pc above the galactic plane. These features may suggest a
unique origin, matching existing evidence of infalling gas parcels interacting
with the disk ISM. Our clustering also suggests links between often-separated
populations, hinting to direct structural connections between Orion Complex and
Perseus OB2, and between the subregions of Vela. The $\sim$30 Myr old
Cepheus-Hercules association is another emerging large-scale structure, with a
size and population comparable to Sco-Cen. Cep-Her and other similarly-aged
structures are also found clustered along extended structures perpendicular to
known spiral arm structure, suggesting that arm-aligned star formation patterns
have only recently become dominant in the solar neighborhood.

Astrophysics of Galaxies;Solar and Stellar Astrophysics