Describe how California's Native nations traded goods such as shell beads and obsidian across long distances before roads or wheels, connecting trade routes to regional resources.
No nation had every resource it needed close by, so California's Native nations traded with each other, long before there were roads, wagons, or cars. People carried goods on their backs along footpaths, or paddled canoes and tule boats along rivers, lakes, and the coast, sometimes traveling great distances to trade.
Trade connected very different regions, the same way you learned that different landforms hold different resources. Nations near the mountains had access to obsidian, a hard, glassy volcanic rock perfect for sharp knives and arrow points, but no ocean shells. Coastal nations had shells for beautiful, valuable beads -- shell beads were so widely wanted that they worked almost like money -- but no obsidian. So an inland trader might carry obsidian toward the coast, trade it for a string of shell beads, and carry the beads back home, and each nation ended up with something it could not make itself.
Mastery looks like: They can explain why California's Native nations traded, name at least one traded good and its origin, and describe how goods traveled without roads or wheels.
Common stumbles: Assuming trade only happened over short distances, or forgetting that both sides of a trade gained something they could not get on their own.