No, they're definitely not open in wet weather. This area and the trails are comprised of clay, not regular dirt, so the moment it starts raining they typically close the tails and tracks. It's like riding in wet slime, not normal mud. They've had people stuck for hours in remote areas, and rescue efforts get stuck too. They're fairly slow to reopen tracks and trails until things have dried out pretty well for the same reason. The Facebook page is updated faithfully, if you follow it you'll be aware of closures and reopening real time. There's also historic posts (do a search if you're curious) explaining why they're more vulnerable to shutdown during wet weather.
Heck ya they better be open. That's when ridings the best tho, they might close some trails due to the trail washed out.
You need to call them and ask because it depends on the trails.
Their Facebook page (search "Metcalf Motorcycle Park") is updated daily with opening times, track closures and special events. Best to check it before heading out. And to answer your question, no, they are not open when it's wet - the place is clay and turns gnarly (not in a good way) as soon as it gets water on it.
No. Not after fresh rain. You can check their updates on Facebook.
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