We have trapped large numbers of copper (Cu) and silver (Ag) atoms using buffer-gas cooling. Up to $3\times {10}^{12}\mathrm{Cu}$ atoms and $4\times {10}^{13}\mathrm{Ag}$ atoms are trapped. Lifetimes are as long as 5 s, limited by collisions with the buffer gas. Ratios of elastic to inelastic collision rates with He are $\gtrsim {10}^6$, suggesting Cu and Ag are favorable for use in ultracold applications. The temperature dependence of the $\mathrm{Ag}\mathrm{\text{−}}{}^3\mathrm{He}$ collision rate varies as $T^{5.8\pm 0.4}$. We find that this temperature dependence is inconsistent with the behavior predicted for relaxation arising from the spin-rotation interaction, and conclude that the $\mathrm{Ag}\mathrm{\text{−}}{}^3\mathrm{He}$ system displays anomalous collisional behavior in the multiple-partial wave regime. Gold (Au) was ablated into ${}^3\mathrm{He}$ buffer gas, however, atomic Au lifetimes were observed to be too short to permit trapping.