It's quick for me in the Denver area, also. Sounds as if it's the specific path between you and this site. If you get in a Windows powershell or other command line interpreter, you can type:
tracert rvforum.net
My response is:
Tracing route to rvforum.net [96.30.5.17]
over a maximum of 30 hops:
1 51 ms 20 ms 29 ms 24.9.12.1
2 10 ms 9 ms 9 ms te-1-2-ur03.arvada.co.denver.comcast.net [68.85.220.1]
3 15 ms 11 ms 11 ms te-0-2-0-2-ar02.denver.co.denver.comcast.net [68.86.179.170]
4 13 ms 15 ms 12 ms pos-0-7-0-0-ar02.aurora.co.denver.comcast.net [68.86.128.246]
5 12 ms 11 ms 11 ms 68.86.87.89
6 13 ms 11 ms 12 ms ae14.edge3.Denver1.Level3.net [4.68.127.129]
7 54 ms 55 ms 54 ms vlan52.ebr2.Denver1.Level3.net [4.69.147.126]
8 54 ms 54 ms 55 ms ae-3-3.ebr1.Chicago2.Level3.net [4.69.132.62]
9 55 ms 63 ms 55 ms 4.69.158.141
10 56 ms 55 ms 64 ms WiredTree.edge4.Chicago2.Level3.net [4.28.68.14]
11 48 ms 50 ms 47 ms vl38.dsw3.chi2.wiredtree.com [173.199.135.230]
12 49 ms 47 ms 47 ms hybrid109e.wiredtree.com [96.30.32.109]
13 47 ms 48 ms 48 ms host.rvforum.net [96.30.5.17]
Trace complete.
and see each hop along the way between you and this site, along with its response time (usually in milliseconds, or ms). Or for a simpler result, you can type:
ping rvforum.net
My response is:
Pinging rvforum.net [96.30.5.17] with 32 bytes of data:
Reply from 96.30.5.17: bytes=32 time=47ms TTL=53
Reply from 96.30.5.17: bytes=32 time=46ms TTL=53
Reply from 96.30.5.17: bytes=32 time=49ms TTL=53
Reply from 96.30.5.17: bytes=32 time=48ms TTL=53
Ping statistics for 96.30.5.17:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 46ms, Maximum = 49ms, Average = 47ms
and get overall response time over multiple tries. This may help you pinpoint where the slowdown is.