Do you need use of all 61 available address ?
Becuase another option that one of the other responders proposed was to put part of the space on the outside interface and part on the inside
like so
int fa 0/0 description inside LAN interface ip addr 70.x.x.98 255.255.255.224 ! default gateway
int fa 0/1 description outside interface facing Verizon FIOS ONT ip addr 70.x.x.66 255.255.255.224 ip proxy-arp ! to answer ARP requests from 70.x.x.1
ip classless ip route 0.0.0.0 0.0.0.0 FastEthernet0/1 70.x.x.1
You can use small block on outside and then add secondary address blocks to inside if you want to go to the bother