Vanguard Prices Public Offering

Vanguard announced the pricing of its public offering of 3,250,000 common units representing limited liability company interests in the Company at a price of $23.00 per unit. The underwriters have been granted a 30-day option to purchase up to an additional 487,500 common units from the Company at the public offering price less the underwriting discount. The offering is expected to settle and close on May 18, 2010, subject to customary closing conditions.

The Company expects to receive net proceeds of approximately $71.5 million (or $82.2 million if the underwriters exercise their option to purchase an additional 487,500 common units), after deducting underwriting discounts and estimated offering expenses, from the offering and intends to use the net proceeds from the offering to repay indebtedness outstanding under its reserve-based credit facility.